A: Upstream speed = 42 - 2 = 14 kmph. Downstream speed = 42 - 14 = 14 kmph. The answer is (C).
Answer the following multiple choice question with options (a), (b), (c), (d), (e).
Q: John found that the average of 15 numbers is 40. If 10 is added to each number then the mean of the numbers is? Answer Choices: (a) 50 (b) 45 (c) 65 (d) 78 (e) 64 
A: The answer is (a). 

Answer the following multiple choice question with options (a), (b), (c), (d), (e).
Q: If a / b = 3/4 and 8a + 5b = 22,then find the value of a. Answer Choices: (a) 1/2 (b) 3/2 (c) 5/2 (d) 4/2 (e) 7/2 
A: The answer is (b). 

Answer the following multiple choice question with options (a), (b), (c), (d), (e).
Q: A person is traveling at 20 km/hr and reached his destiny in 2.5 hr then find the distance? Answer Choices: (a) 53 km (b) 55 km (c) 52 km (d) 60 km (e) 50 km 
A: The answer is (e). 

Answer the following multiple choice question with options (a), (b), (c), (d), (e).
Q: How many keystrokes are needed to type the numbers from 1 to 500? Answer Choices: (a) 1156 (b) 1392 (c) 1480 (d) 1562 (e) 1788 
A: The answer is (b).

Answer the following multiple choice question with options (a), (b), (c), (d), (e).
The time taken by a man to row his boat upstream is twice the time taken by him to row the same distance downstream. If the speed of the boat in still water is 42 kmph, find the speed of the stream? Answer Choices: A)77 B)88 C)14 D)12 E)17