Q: A 400 meter long train crosses a man standing on the platform in 10 sec. What is the speed of the train?
Options:
(A) 144
(B) 108
(C) 278
(D) 126
(E) 112
A: OK... Stream of consciousness: S = 400/10 * 18/5 = 144 kmph
The answer is (A).

Q: On 3,000 invested at a simple interest rate 6 p.c.p.a, 900 is obtained as interest in certain years. In order to earn 1,600 as interest on 4,000 in the same number of years, what should be the rate of simple interest?
Options:
(A) 7 p.c.p.a.
(B) 8 p.c.p.a.
(C) 9 p.c.p.a.
(D) Data inadequate
(E) None of these
A: OK... Stream of consciousness: Time = 900100/30006 = 5 years
Rate = 1600100/54000 = 8%
The answer is (B).

Q: Four of the following five parts numbered (a), (b), (c), (d) and (e) in the following equation are exactly equal. Which of the parts is not equal to the other four? The number of that part is the answer.
Options:
(A) xy2 x2y + 2x2y2
(B) xy2(1 2x) + x2y(2y 1)
(C) xy2(1 + x) x2y(1 y)
(D) xy[y(1 + x) x(1 y) ]
(E) xy(y x + 2xy)
A: OK... Stream of consciousness: The other parts are equal to xy2 x2y + 2x2y2.
The answer is (B).

Q: Rs.500 amounts to Rs.620 in 2 years at simple interest. If the interest is increased by 2%, it would amount to how much?
Options:
(A) 120
(B) 25
(C) 614
(D) 530
(E) 210
A:
OK... Stream of consciousness: (500*3*2)/100 = 30
500+ 30 = 530
The answer is (D).