Question: John found that the average of 15 numbers is 40. If 10 is added to each number then the mean of the numbers is?
Options: (a) 50 (b) 45 (c) 65 (d) 78 (e) 64
Answer: If 10 is added to each number, then the mean of the numbers also increases by 10. So the new mean would be 50. The answer is (a).

Question: If a / b = 3/4 and 8a + 5b = 22,then find the value of a.
Options: (a) 1/2 (b) 3/2 (c) 5/2 (d) 4/2 (e) 7/2
Answer: a / b = 3/4, then b = 4a / 3. So 8a + 5(4a / 3) = 22. This simplifies to 8a + 20a / 3 = 22, which means 44a / 3 = 22. So a is equal to 3/2. The answer is (b).

Question: A person is traveling at 20 km/hr and reached his destiny in 2.5 hr then find the distance?
Options: (a) 53 km (b) 55 km (c) 52 km (d) 60 km (e) 50 km
Answer: The distance that the person traveled would have been 20 km/hr * 2.5 hrs = 50 km. The answer is (e).

Question: How many keystrokes are needed to type the numbers from 1 to 500?
Options: (a) 1156 (b) 1392 (c) 1480 (d) 1562 (e) 1788
Answer: There are 9 one-digit numbers from 1 to 9. There are 90 two-digit numbers from 10 to 99. There are 401 three-digit numbers from 100 to 500. 9 + 90(2) + 401(3) = 1392. The answer is (b).