q: At what rate percent on simple interest will a sum of money double itself in 70 years?
Options:
(A) 1 3/7%
(B) 3 1/9%
(C) 3 9/3%
(D) 3 2/3%
(E) 3 6/3%
a: P = (P*70*R)/100
R = 1 3/7% The answer is (A).
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q: A train 250 m long running at 72 kmph crosses a platform in 20 sec. What is the length of the platform?
Options:
(A) 150m
(B) 200m
(C) 250m
(D) 270m
(E) 300 m
a: D = 72 * 5/18 = 20 = 400 250 = 150m The answer is (A).
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q: How should be added in order to make 2345672 this number is divisible by 9?
Options:
(A) 5
(B) 6
(C) 7
(D) 8
(E) 9
a: Sum of the numbers 2345672 is 29 which is not multiple of 9
Add 7 which makes the sum 36 which is multiple of 9
So digit becomes 2345679 (as we know that if sum multiple of 9 then it is divisible of 9) The answer is (C).
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q: In a staircase, there ar 10 steps. A child is attempting to climb the staircase. Each time she can either make 1 step or 2 steps. In how many different ways can she climb the staricase?
Options:
(A) 23
(B) 277
(C) 18
(D) 178
(E) 181
a:
Use fibonnacci series, with starting two terms as 1, 2. So next terms are 3, 5, 8, 13, 21, 34, 55, 89 The answer is (B).
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