Rationale: Speed = 63 * 5/18 = 35/2 m/sec
Time taken = 210 * 2/35 = 12 sec
The answer: (D)
Question: A train 210 m long, running with a speed of 63 km/hr will pass a tree in?
Options:
(A) 15 sec
(B) 16 sec
(C) 18 sec
(D) 12 sec
(E) 25 sec
Reasoning: 9 is divisible by 3. So, it is not a prime number.
Ans: (D)
Question: Which one of the following is not a prime number?
Options:
(A) 2
(B) 3
(C) 5
(D) 9
(E) 7
Rationale: We need to make 1152x a perfect cube, hence we need to have the powers a multiple of 3
1152 = 2^7*3^2
The minimum value of x for which 1152x is a perfect cube = 2^2*3 = 12
The answer: (D)
Question: What is the smallest positive integer x, such that 1,152x is a perfect cube?
Options:
(A) 4
(B) 6
(C) 8
(D) 12
(E) 18
Reasoning: Option(B) is correct
P(Both are red), 6C2/13C2 = 5/26
Ans: (B)
Question: An urn contains 6 red, 5 blue and 2 green marbles. If 2 marbles are picked at random, what is the probability that both are red?
Options:
(A) 6/13
(B) 5/26
(C) 6/26
(D) 9/26
(E) 10/27
Rationale: K + 3K +3 + 3K - 4 + 5K +1 = 12K
(12K)/4 = 60
12K = 60 * 4 = 240
K = 240/ 12 = 20.
The answer: (C)
Question: If the average (arithmetic mean) of the four numbers K, 3K + 3, 3K 4 and 5K + 1 is 60, what is the value of K?
Options:
(A) 11
(B) 15 3/4
(C) 20
(D) 23
(E) 25 3/10
Rationale: Say May income = 100
L's income = 60 and rest of the family = 40
In June L's income = 60 * 120 /100 = 72
So 72 /72 + 40 = 64%
The answer: (A)
Question: In May Mrs Lee's earnings were 60 percent of the Lee family's total income. In June Mrs Lee earned 20 percent more than in May. If the rest of the family's income was the same both months, then, in June, Mrs Lee's earnings were approximately what percent of the Lee family's total income ?
Options:
(A) 64%
(B) 68%
(C) 72%
(D) 76%
(E) 80%