Reasoning: There are 31 students and every one has equal chance of being selected as a leader. Hence, the leader can be appointed in 31 ways. When one person is appointed as leader, we are left with 35 students. Out of these 30 teachers, we can select one class representative. So, a class representative can be selected in 30 ways. Hence, the number of ways in which a leader and class representative can be selected = 31 x 30 = 930
Ans: (E)
Question: From among the 31 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) 1160
(E) 930
Rationale: 142 + 110 = 252/14 = 18 (Remainder)
The answer: (C)
Question: A no.when divided by 142 gives a remainder 110, what remainder will be obtainedby dividingthe same no.14?
Options:
(A) 16
(B) 17
(C) 18
(D) 19
(E) 20
Reasoning: Formula = Third proportional = (b b)/a
A = 9 and B = 12
(12 12)/ 9 = 144/9 = 16
Ans: (C)
Question: Find the third proportional to 9 and 12?
Options:
(A) 10
(B) 12
(C) 16
(D) 19
(E) 20
Rationale: Left After 1st stroke = 1/2
Left After 2nd stroke = 1/2 * 1/2 = 1/4
So removed = 1- 1/4 = 3/4
The answer: (A)
Question: If 1/2 of the air in a tank is removed with each stroke of a vacuum pump, what fraction of the original amount of air has been removed after 2 strokes ?
Options:
(A) 3/4
(B) 7/8
(C) 1/4
(D) 1/8
(E) 1/16
Reasoning: (9+5) +2 = 16
(16+9) +3 = 28
(28+16)+4 = 48
(48+28)+5 = 81
Ans: (C)
Question: 5,9,16,28,48,__
Options:
(A) 79
(B) 80
(C) 81
(D) 82
(E) 83
Reasoning: Only 4 cubes situated at the corners of the cuboid will have 4 coloured and 2 non-coloured sides.
Ans: (B)
Question: How many cubes will have 4 coloured sides and two non-coloured sides ?
Options:
(A) 5
(B) 4
(C) 3
(D) 2
(E) 1