q: A train 150 m long running at 72 kmph crosses a platform in 25 sec. What is the length of the platform?
Options:
(A) 338
(B) 277
(C) 350
(D) 881
(E) 271
a: OK... D = 72 * 5/18 = 25 = 500 150 = 350
The answer is (C).

q: M and N invested in a shop. The profits were divided in the ratio of 4 : 5 respectively. If M invested Rs. 40,000, the amount invested by N is:
Options:
(A) 35000
(B) 40000
(C) 50000
(D) 60000
(E) None
a: OK... Suppose N invested Rs. x. Then, 40000/x = 4/5 or y = [40000 x 5/ 4] = 50000.
The answer is (C).

q: Calculate the speed of a boat in still water (in km/hr) if in one hour, the boat goes 10 km/hr downstream and 4 km/hr upstream.
Options:
(A) 7 kmph
(B) 8 kmph
(C) 9 kmph
(D) 7 kmph
(E) 6 kmph
a:
OK... Speed in still water = (10 + 4)1/2 kmph = 7 kmph.
The answer is (A).