Amex American Express Data Science ML Role MCQS PYQS

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"Pattern you can expect: 3 Sections: ### LR/DI/Abstract Reasoning - 24 MCQS ### Numerical Abilityl and Stats - 24 MCQS ### Coding(ML/Python/SQL) - 12 MCQS ### Problem 1: Average Recycle Figure The following bar graph shows the recycle of cellular phones during 2013 to 2018. What is the average recycle figure of all the years?  ### Problem 2: Total Profit for Companies The table below shows the quarterly profits (in thousands) of three companies (X, Y, Z) for the year 2022. What is the total profit for all companies combined over the entire year?  ### Problem 3: Family Relations M is N's grandfather. O is M's only son. P is O's daughter. What is N's relation to P? ### Problem 4:  ### Problem 5:  ### Problem 6 A boat travels upstream at 5 km/h and downstream at 10 km/h. If the total time taken for the journey is 6 hours, what is the distance traveled upstream? - 15 km - 20 km - 25 km ### Problem 7 A team of 12 workers can complete a task in 15 days working 7 hours a day. If the team increases to 18 workers working 10 hours a day, how many days will it take to complete the same task? - 6 - 7 - 8 - 9 ### Problem 8 A man buys goods for $4000 and sells half of them at a loss of 10% and the other half at a gain of 15%. What is his overall gain or loss percentage? - 2.5% loss - 2.5% gain - 5% gain - 5% loss ### Problem 9 A and B can do a piece of work in 15 days and 20 days respectively. They work together for 5 days, then B leaves. How many more days will A take to finish the remaining work? - 6 days - 7.25 days - 6.5 days - 6.25 days ### Problem 10 A trader buys two articles for $500 each. He sells one at a gain of 20% and the other at a loss of 20%. What is his overall gain or loss percentage? ### Problem 11 A car covers a distance of 150 km at a speed of 50 km/h and returns at 75 km/h What is the average speed for the whole journey? ### Problem 12 The ratio of the ages of A and B is 3:5. If the sum of their ages is 64 years, what will be the ratio of their ages after 8 years? ### Problem 13 Party A and Party B are competing in an election, conducted in a village of 4800 people, Party A was predicted to win, but on the day of the election a third of the voters of Party A were kidnapped. Party B was also able to convince some of the remaining voters for Party A and double its vote bank. Party A ended up losing by a majority which was half of that by which it would have won had the elections been fair. How many people finally voted for Party A and Party B? ### Problem 14 A plantation grows three types of flowers: daisies, lilies, and tulips. They plant these flowers in a ratio of 6:3:2. There are 144 more daisies planted than tulips. How many tulips are planted? ### Problem 15 A study shows that the mean number of hours spent on social media by teenagers in a week is 15 hours with a standard deviation of 4 hours. Assuming the distribution of hours spent is approximately normal, what percentage of teenagers spend between 11 and 19 hours on social media per week? ### Problem 16 In a normal distribution, 68% of the data falls within one standard deviation of the mean, 95% within two, and 99.7% within three, If a dataset of 10,000 points has a mean of 100 and exactly 9,500 points fall within two standard deviations, what is the standard deviation? - 12.5 - 13.5 - 14.5 - 15.5 ### Problem 17 A dataset contains 100 numbers. When each number is increased by 5, the mean increases by 5 and the variance decreases by 20%. What was the original variance of the dataset? - 100 - 125 - 150 - 175 ### Problem 18 A weighted die has probabilities proportional to the numbers on its faces. If the probability of rolling a 6 is 0.3, what is the expected value of a roll? ### Problem 19 In a group of 600 people, the mean age is 40 years. If 150 people with a mean age of 30 years join the group, what is the mean age of the new group? ### Problem 20 In a group of 500 people, the mean age is 35 years. If 100 people with a mean age of 25 years leave the group, what is the mean age of the remaining group? ### Problem 21 A common scenario in athletic training involves two runners, designated as Runner A and Runner B, navigating a perfectly circular track. Runner A possesses the capability to complete a full circuit of this track in precisely 20 minutes, demonstrating a consistent pace. In contrast, Runner B requires an additional 5 minutes, completing the same circular path in 25 minutes. Both athletes commence their respective runs from the identical starting position and simultaneously begin their motion, proceeding in the exact same direction around the track. The intriguing question that arises is: following their simultaneous departure, after how many minutes will both Runner A and Runner B next converge at their shared starting point? ### Problem 22 In an intricate game of chance and numerical strategy, participants are tasked with repeatedly rolling a specially designed 11-sided die. This die is perfectly fair, meaning each of its faces, uniquely numbered from 1 to 11, has an equal chance of landing face up. The central objective of this particular game phase is to continue rolling the die until the ongoing product of all the numbers rolled sequentially achieves divisibility by 12. This creates an escalating numerical challenge for the player. Given these precise rules governing the game mechanics, this scenario poses a fundamental question: what is the exact probability that the cumulative product will become divisible by 12 for the very first time on the third roll, and not on any preceding roll? - 221/1331 - 243/1331 - 265/1331 - 287/1331 ### Problem 23 In the current annual cycle, precisely on the third Thursday of April, a direct comparison to the preceding year's calendar reveals a notable shift: this exact same calendar date, observed twelve months prior, had fallen specifically on a Tuesday. Given this established chronological relationship between the current year and the one immediately preceding it, a compelling challenge emerges: to accurately determine the precise day of the week upon which this identical April date will ultimately land, a full seven years into the future from our present point in time, thereby establishing its future temporal alignment. ### Problem 24 A vessel navigates a body of water, where its intrinsic speed when the water is perfectly still is measured at 15 kilometers per hour. Concurrently, the moving current of the water itself exhibits a speed of 3 kilometers per hour. The boat embarks on a journey, covering a distance of 48 kilometers while proceeding downstream, with the assistance of the current. Following this, it undertakes the return leg of its journey, traveling back to its precise original starting point against the current. The entire round trip, encompassing both the downstream and upstream segments, is completed in a total duration of 7 hours. Given these specific speeds and the total time taken for the round trip, the fundamental task is to ascertain the precise distance, in kilometers, that the boat traversed during its upstream travel. - 24 km - 28 km - 32 km - 36 km ### Problem 25 Sumit and Amit start running towards each other from two points X and Y, which are 0.5 km apart. Sumit runs at 36 km/h and Amit at 54 km/h Upon reaching the other end, each immediately turns back without delay and continues running at the same speed. At what distance from point X will they meet for the second time? ### Problem 26 In a metallurgical challenge, a metallurgist has access to four distinct alloys, each characterized by a unique ratio of copper to zinc. The first alloy presents copper and zinc in a ratio of 2:3, followed by a second alloy with a 3:5 proportion. The third alloy is composed of these metals in a 5:7 ratio, and finally, the fourth alloy contains them in a 7:9 ratio. The objective is to precisely combine quantities of these four source alloys to produce a final alloy mixture that weighs exactly 100 grams. This ultimate mixture must, crucially, exhibit a specific desired ratio of copper to zinc, which is 14:19. The pivotal question, therefore, is to ascertain the exact mass, in grams, that must be drawn from each of the initial four alloys to achieve this very specific compositional and mass requirement. - 15, 25, 30, 30 - 10, 20, 30, 40 - 20, 30, 25, 25 - 25, 25, 30, 20 ### Problem 27 In a quantum mechanics seminar, Dr. Lee considers the function f(x) = ln(x)/x for x > 1. She asks: at which x-value does this function attain its maximum? ### Problem 28 A firm is engaged in breeding pigs. The pigs are fed on various products grown on the farm. In view of the need to ensure certain nutrients constituents (call them X, Y and Z), It is necessary to buy two additional products, say A and B. One unit of product A contains 36 units of nutrient X, 3 units of nutrient Y and 20 units of nutrient Z. One unit of product B contains 6 units of nutrient X, 12 units of nutrient Y and 10 units of nutrient Z. The minimum requirement of nutrients X, Y and Z is 108 units, 36 units and 100 units respectively. Product A costs 20 per unit and product B costs 40 per unit. Formulate the above as a linear programming problem to minimize total cost. ### Problem 29 You are designing a database for an online bookstore. Each book has a unique ISBN number. How would you define the primary key for the 'Books' table? - PRIMARY KEY (BookID) - PRIMARY KEY (ISBN) - UNIQUE KEY (ISBN) - FOREIGN KEY (ISBN) REFERENCES Publishers (ISBN) ### Problem 30 You are performing multiple update operations on a table named Orders. Midway through, an error occurs. You need to ensure that either all changes are committed or none at all to maintain data integrity. Which SQL command should you use to meet this requirement? - USE TRANSACTION - BEGIN TRANSACTION - SET 'ISOLATION LEVEL' - ENABLE 'AUTOCOMMIT' ### Problem 31 Eve wants to learn about the type of transaction. Help her in identifying which of the following is the valid transaction type in MS Sql? - Implicit Transaction - Auto Transaction - NULL Transaction - None of These ### Problem 32 An analyst is utilizing Bayesian regression to model financial returns during different market conditions and intends to incorporate quantile regression to assess the impact of extreme market movements more robustly. Given the model's complex nature and the highly skewed nature of financial returns, specific adjustments are considered. What is the most appropriate next step for refining this model to capture the tails of the return distribution more accurately? - Adjust the quantile in the quantile regression to 0.5 to ensure the median is accurately captured, enhancing model stability. - Apply a heavier-tailed prior distribution in the Bayesian model to better accommodate outliers in financial returns. - Increase the complexity of the Bayesian model by adding more predictors to cover various market conditions. - Shift the focus from Bayesian to frequentist regression models to avoid the subjectivity of prior distribution choice. ### Problem 33 Which one of the following a valid testing function name? - addtesting - addtest - test_add - addtestingfunction ### Problem 34 Why is it advised not to set a function parameter as an empty list as a default value? - because list is a mutable data type and everytime that function will be called the func will use the sarne list - because list will consume a lot of memory - because we can't assign empty list a function parameter - because it we looks weird to see a list as a default value ### Problem 35 You are developing a KNN-based system for a retail company to classify customer reviews into sentiment categories. The dataset contains thousands of textual reviews that are high-dimensional after vectorization, Considering the high dimensionality of your dataset, which technique would be most effective to improve the performance and accuracy of your KNN model? - Increase the value of K to reduce the noise in the classification. - Implement dimensionality reduction techniques like PCA to reduce the curse of dimensionality. - Use Mahalanobis distance for nuanced high-dimensional space analysis. - Convert to a weighted KNN approach, assigning higher weights to nearer neighbors. ### Problem 36 You are implementing a KNN algorithm to classify audio clips into various genres for a music streaming service. The data includes features derived from both temporal and spectral analyses of the audio clips. To optimize the KNN classifier for this audio classification task, considering the nature of the data, which preprocessing step is most critical to improve model accuracy? - Normalize the feature set to ensure each feature contributes equally to the distance computation. - Increase the K value significantly to smooth out the prediction across more neighbors: - Focus on removing outlier clips that might skew the distance measurements. - Implement an aggressive feature selection to reduce the data to only temporal features. ### Problem 37 A multinational company has a distributed SQL, database system spanning multiple geographic locations. They experience significant latency issues and data inconsistency due to network partitions and asynchronous replication. The goal is to achieve strong consistency while maintaining high availability and minimizing latency. Given the CAP theorem constraints, which strategy should the company implement to achieve strong consistency and how should they mitigate potential downsides? - Implementing synchronous replication across all nodes to ensure strong consistency, and employing a robust retry mechanism for high availability. - Utilizing a leader-follower architecture where all writes go to a single leader node, and using eventual consistency for reads from follower nodes to reduce latency. - Adopting a quorum-based approach for both reads and writes, ensuring that a majority of nodes agree on any data change, while using a read repair mechanism to handle inconsistencies. - Enabling conflict-free replicated data types (CRDTs) to handle concurrent updates across nodes, ensuring strong eventual consistency and reducing write conflicts. ### Problem 38 What will be the output of the script, and why? class V: def process(self): return "Processed by Y" class X(V): def process(self): return "Processed by X" class Y(V): def process(self): return "Processed by Y" class Z(X, Y): def process(self): return super().process() class W(Z, Y): pass w_instance = W() print(w_instance.process()) - Processed by X-MRO follows the chain starting from X - Processed by Y- MRO follows the chain starting from Y - Processed by ZMRO stops at the method in Z - Processed by W-MRO selects the method in W ### Problem 39 A financial analytics team is using Gradient Boosting Machines (GBM) for forecasting market trends. They observe that their model struggles during sudden market changes, leading them to consider parameter adjustments for better responsiveness. from sklearn.ensemble import GradientBoostingRegressor model = GradientBoostingRegressor(n_estimators=100, learning_rate=0.1, max_depth=3, min_samples_split=2, random_state=42) model.fit(X_train, y_train) Given the need to enhance the GBM model's responsiveness to sudden market shifts, which modification to the code would most effectively allow the model to adapt to rapid changes and reduce forecasting errors? - Change learning_rate=0.1 to learning_rate=0.01 to slow the training process, focusing more closely on capturing new market trends. - Modify n_estimators=100 to n_estimators=200 to increase the number of sequential trees, potentially improving model robustness. - Adjust min_samples_split=2 to min_samples_split=10 to allow more detailed node splits, capturing finer market nuances. - Update max_depth=3 to max_depth=5 to allow deeper trees that can identify more complex patterns during volatile market periods. ### Problem 40 What is the output for the following code? def __init__(self, start, step, limit): self.current = start self.step = step self.limit = limit def __iter__(self): return self def __next__(self): if self.current > self.limit: raise StopIteration value = self.current self.current += self.step return value series = NumberSeries(1, 2, 9) for num in series: print(num) - 1 3 5 7 9 - 1 2 3 4 5 - 2 4 6 8 10 - 1 2 3 4 5 6 7 8 9 ### Problem 41  ### Problem 42  ### Problem 43  ### Problem 44  ### Problem 45 "