q: The average age of A, B and C is 28 years. If the average age of A and C is 29 years, what is the age of B in years ?
Options:
(A) 19
(B) 26
(C) 20
(D) 32
(E) 21
a: OK... Age of B = Age of (A + B + C) Age of (A + C) = 28 3 29 2 = 84 58 = 26 years
The answer is (B).

q: From among the 39 students in a class, one leader and one class representative are to be appointed. In how many ways can this be done?
Options:
(A) 1360
(B) 1260
(C) 1060
(D) 1482
(E) 1460
a: OK... There are 39 students and every one has equal chance of being selected as a leader. Hence, the leader can be appointed in 39 ways. When one person is appointed as leader, we are left with 35 students. Out of these 38 teachers, we can select one class representative. So, a class representative can be selected in 38 ways. Hence, the number of ways in which a leader and class representative can be selected = 39 x 38 = 1482
The answer is (D).

q: A man purchased 3 blankets @ Rs.100 each, 5 blankets @ Rs.150 each and two blankets at a certain rate which is now slipped off from his memory. But he remembers that the average price of the blankets was Rs.150. Find the unknown rate of two blankets?
Options:
(A) 278
(B) 277
(C) 278
(D) 450
(E) 272
a:
OK... 10 * 150 = 1500
3 * 100 + 5 * 150 = 1050
1500 1050 = 450
The answer is (D).