Answer: A) 21 Explanation: The given number series follows a pattern that, 19 + 12 = 20 (not 21)20 + 22 = 2424 + 32 = 3333 + 42 = 4949 + 52 = 74    Hence, the odd number in the given number series is 21.

Answer: B) Rs.17,500 Explanation: Let’s assume John bought the laptop for Rs. 100He then sells it to Mark at a loss of 20% => Rs. 80,Who consequently sells it to Kevin at a profit of 25% =>  Rs. 100Then, Kevin sells it back to Mark for Rs. 90 (Rs.4.50 for every Rs. 5 that he had paid initially), so he suffers a loss of Rs. 10Therefore, for Rs. 100 there is a loss of Rs. 10,Then for Rs. 1,75,000 there will be a loss of Rs. 17,500.