Rationale: K + 2K +3 + 4K - 4 + 5K +1 = 12K
(12K)/4 = 63
12K = 63 * 4 = 252
K = 252 / 12 = 21
The answer: (C)
Question: If the average (arithmetic mean) of the four numbers K, 2K + 3, 4K 4 and 5K + 1 is 63, what is the value of K?
Options:
(A) 11
(B) 15 3/4
(C) 21
(D) 23
(E) 25 3/10
Reasoning: Simple interest = (18000 * 4 * 15)/100 = Rs. 10800
Amount = P + I = 18000 + 10800 = Rs. 28800
Ans: (A)
Question: What amount does Kiran get if he invests Rs. 18000 at 15% p.a. simple interest for four years?
Options:
(A) 28800
(B) 24800
(C) 24400
(D) 20000
(E) None
Rationale: 54*10 = 540
66*5 = 330
870/15 = 58
The answer: (B)
Question: If 10 litres of an oil of Rs.54 per litres be mixed with 5 litres of another oil of Rs.66 per litre then what is the rate of mixed oil per litre?
Options:
(A) Rs.49.17
(B) Rs.58
(C) Rs.54.17
(D) Rs.55.33
(E) None of the above
Reasoning: Speed downstream = d/t = 80/(3) = 27 kmph
Speed upstream = d/t = 38/(3) = 9 kmph
The speed of the stream = (27 - 9)/2 = 9 kmph
Ans: (B)
Question: A man rows his boat 80 km downstream and 38 km upstream, taking 3 hours each time. Find the speed of the stream?
Options:
(A) 6
(B) 9
(C) 7
(D) 8
(E) 2
Rationale: Rate of H = 6 acres/hr
Remaining land to be harvested = 100 - 40 = 60
Rate of H and K = 60/6 = 10 acres/hr
Rate of K = 10 - 6 = 4
The answer: (A)
Question: A farm used two harvesting machines, H and K, to harvest 100 acres of wheat. Harvesting machine H, working alone at its constant rate, harvested 40 acres of wheat in 8 hours. Then harvesting machine K was brought in, and harvesting machines H and K, working together at their respective constant rates, harvested the remaining acres of wheat in 6 hours. Harvesting machine K harvested how many acres of wheat per hour?
Options:
(A) 4
(B) 8
(C) 12
(D) 13
(E) 15
Rationale: X * (85/100) = 85000
X = 1000 * 100
X = 100000
The answer: (C)
Question: 85% of the population of a city is 85000. The total population of the city is?
Options:
(A) 95000
(B) 97500
(C) 100000
(D) 105000
(E) 102500