Rationale: Final number = Initial number + 50%(original number) = 90 + 50%(90) = 90 + 45 = 135.
The answer: (C)
Question: 90 is increased by 50%. Find the final number.
Options:
(A) 100
(B) 110
(C) 135
(D) 140
(E) 160
Reasoning: S = 180/9 * 18/5 = 72 kmph
Ans: (A)
Question: A 180 meter long train crosses a man standing on the platform in 9 sec. What is the speed of the train?
Options:
(A) 72
(B) 108
(C) 1266
(D) 188
(E) 211
Rationale: Speed of the train, v = 40 km/hr = 40000/3600 m/s = 400/36 m/s
Time taken to cross, t = 18 s
Distance Covered, d = vt = (400/36) 18 = 200 m
Distance covered is equal to the length of the train = 200 m
The answer: (E)
Question: A train is running at a speed of 40 km/hr and it crosses a post in 18 seconds. What is the length of the train?
Options:
(A) 190 metres
(B) 160 metres
(C) 180 metres
(D) 120 metres
(E) 200 metres
Reasoning: A's 1 hour work = 1/4;
(B + C)'s 1 hour work = 1/3;
(A + C)'s 1 hour work = 1/2
(A + B + C)'s 1 hour work = (1/4 + 1/3) = 7/12
B's 1 hour work = (7/12 + 1/2) = 1/12
B alone will take 12 hours to do the work.
Ans: (C)
Question: A can do a piece of work in 4 hours; B and C together can do it in 3 hours, which A and C together can do it in 2 hours. How long will B alone take to do it?
Options:
(A) 11
(B) 77
(C) 12
(D) 99
(E) 02
Rationale: 67 + 71 + 73 + 79 + 83 + 89 = 462/6 = 77
The answer: (B)
Question: The average of first six prime numbers greater than 65 is?
Options:
(A) 55
(B) 77
(C) 56
(D) 67
(E) 98
Rationale: Area of the outer rectangle = 23 16 = 368 m2
Area of the inner rectangle = 19 12 = 228 m2
Required area = (368 228) = 140 m2
The answer: (B)
Question: The floor of a rectangular room is 19 m long and 12 m wide. The room is surrounded by a veranda of width 2 m on all its sides. The area of the veranda is :
Options:
(A) 144 m2
(B) 140 m2
(C) 108 m2
(D) 158 m2
(E) None of these