Reasoning: Formula = Third proportional = (b b)/a
A = 3 and B = 9
(9 x 9)/ 3 = 81/3 = 27
Ans: (C)
Question: Find the third proportional to 3 and 9?
Options:
(A) 10
(B) 12
(C) 27
(D) 19
(E) 20
Rationale: 7f/30 tells us that f is a factor of 30, which has 2, 3, and 5 as its prime factors. Each of them is distinct. Moreover, all multiples of 30 less than 200 can be derived by multiplying these prime factors alone. Thus, number of different prime factors is 3.
The answer: (B)
Question: In f is a positive integer smaller than 200 and (14f)/60 is an integer, then f has how many different positive prime factors?
Options:
(A) 2
(B) 3
(C) 5
(D) 6
(E) 8
Reasoning: A = 2000(21/20)2 = 2205
Ans: (A)
Question: A money lender lends Rs.2000 for six months at 20% p.a. rate. It the interest is reckoned quarterly than find the amount given after time limit?
Options:
(A) 2205
(B) 8786
(C) 8275
(D) 2872
(E) 2282
Rationale: (600*3*4)/100 = 72
600 + 72 = 672
The answer: (A)
Question: Rs.600 amounts to Rs.900 in 3 years at simple interest. If the interest is increased by 4%, it would amount to how much?
Options:
(A) 672
(B) 246
(C) 258
(D) 856
(E) 653
Reasoning: Speed downstream = d/t = 85/(2 1/2) = 34 kmph
Speed upstream = d/t = 45/(2 1/2) = 18 kmph
The speed of the stream = (34 - 18)/2 = 8 kmph
Ans: (D)
Question: A man rows his boat 85 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?
Options:
(A) 5 kmph
(B) 7 kmph
(C) 9 kmph
(D) 8 kmph
(E) 1 kmph
Reasoning: Speed = 60 * 5/18 = 50/3 m/sec
Length of the train = speed * time = 50/3 * 6 = 100 m
Ans: (D)
Question: A train running at the speed of 60 km/hr crosses a pole in 6 sec. What is the length of the train?
Options:
(A) 356
(B) 278
(C) 127
(D) 100
(E) 150