Q: What approximate value should come in place of question mark (?) in the following equation
287.532 + 1894.029 657.48 = 743.095 + ?
Options:
(A) 870
(B) 790
(C) 780
(D) 770
(E) 890
A: OK... Stream of consciousness: ? = 285 + 1895 655 745 or, ? = 780
The answer is (C).

Q: Ravi can do a piece of work in 30 days while Prakash can do it in 40 days. In how many days will they finish it together?
Options:
(A) 17 1/7
(B) 17 1/9
(C) 17 1/2
(D) 17 1/7
(E) 17 1/5
A: OK... Stream of consciousness: 1/30 + 1/40 = 7/120
120/7 = 17 1/7 days
The answer is (A).

Q: he population of a city is 140,000. If it increases at the rate of 6% per annum, then what will be its population 2 years hence?
Options:
(A) 1797787
(B) 1597723
(C) 159776
(D) 159728
(E) 157304
A: OK... Stream of consciousness: Population after n years = P [1 + (R/100)]2
Population after 2 years = 140000 * [1 + 6/100]2 = (160000 x 53/50 x 53/50) = 157304
The answer is (E).

Q: The speed of a boat in still water is 60kmph and the speed of the current is 20kmph. Find the speed downstream and upstream?
Options:
(A) 35, 25 kmph
(B) 80, 40 kmph
(C) 40, 60 kmph
(D) 50, 55 kmph
(E) 50, 65 kmph
A:
OK... Stream of consciousness: Speed downstream = 60 + 20 = 80 kmph
Speed upstream = 60 - 20 = 40 kmph
The answer is (B).