Rationale: Total expenditure = 40 + 25 + 15 + 5 = 85%
Saving = (100 - 85) = 15%
15/100 Salary = 2700, Salary = 18000 Rs.
The answer: (C)
Question: A person spends 40% of his salary on food, 25% on house rent, 15% on entertainment and 5% on conveyance. If his savings at the end of the month is Rs. 2700, then his salary per month in rupees is:
Options:
(A) 4000
(B) 6000
(C) 18000
(D) 10000
(E) None of these
Reasoning: We have 1, 8, 27 and 64 as perfect cubes from 1 to 100. Thus, the probability of picking a perfect cube is 4/100 = 1/25
Ans: (A)
Question: If a number is chosen at random from the set {1, 2, 3, 100}, then the probability that the chosen number is a perfect cube is
Options:
(A) 1/25
(B) 1/2
(C) 4/13
(D) 1/10
(E) 3/10
Rationale: Six persons can be arranged in a row in 6! ways. Treat the three persons to sit together as one unit then there four persons and they can be arranged in 4! ways. Again three persons can be arranged among them selves in 3! ways. Favourable outcomes = 3!4! Required probability = 3!4!/6! = 1/5
The answer: (C)
Question: If six persons sit in a row, then the probability that three particular persons are always together is?
Options:
(A) 1/6
(B) 1/3
(C) 1/5
(D) 1/1
(E) 1/2
Reasoning: Average of 20 numbers = 0
Sum of 20 numbers = (0 * 20) = 0
It is quite possible that 19 of these numbers may be positive and if their sum is a, then 20th number is (-a).
Ans: (D)
Question: The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?
Options:
(A) 7
(B) 4
(C) 12
(D) 19
(E) 28
Rationale: 1 /3+ 1/6 = 1 /2 Together they will take, 1/ 1/2 = 2
The answer: (C)
Question: Rita can knit a pair of socks in 3 days. Sita can knit the same in 6 days. If they are knitting together, in how many days will they knit two pairs of socks.
Options:
(A) 4
(B) 1
(C) 2
(D) 5
(E) 6
Rationale: 70 + 50 = 120 * 5/18 = 100/3 mps
D = 150 + 100 = 250 m
T = 250 * 3/100 = 15/2 = 7 1/2 sec
The answer: (D)
Question: Two trains are moving at 50 kmph and 70 kmph in opposite directions. Their lengths are 150 m and 100 m respectively. The time they will take to pass each other completely is?
Options:
(A) 7 1/6 sec
(B) 7 3/2 sec
(C) 7 1/7 sec
(D) 7 1/2 sec
(E) 3 3/2 sec