A: The total distance covered by the train in the tunnel is 3.5 * 100 = 3500 meters. Speed = 72 * 5/18 = 40m/s. Time taken = 3500/40 = 3 minutes. The answer is (A).
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).
A train with a length of 100 meters, is traveling at a speed of 72 km/hr. The train enters a tunnel 3.5 km long. How many minutes does it take the train to pass through the tunnel from the moment the front enters to the moment the rear emerges? Answer Choices: A)3 B)4.2 C)3.4 D)5.5 E)5.7