q: If the ratio of boys to girls in a class is B and the ratio of girls to boys is G; then 10 (B + G) is ?
Options:
(A) Equal to 3
(B) Less than 3
(C) More than 3
(D) Less than 1/3
(E) none of these
a: Stream of consciousness: Let number of boys = x
Let number of girls = y
Therefore x/y = B and y/x = G
10(B + G) = 10[(x/y) + (y/x)] = 10[(x2 + y2)/xy] > 10 The answer is (E).

question: There are 6561 balls out of them 1 is heavy.Find the min. no. of times the balls have to be weighed for finding out the haevy ball.
Options:
(A) 7
(B) 8
(C) 9
(D) 10
(E) 11
answer: Stream of consciousness: The simple logic is to divide total balls into three sets. Weigh any two sets against each other(these two must contain equal number of balls). From this we can identify which set contains the heavy ball. Divide this set into three and repeat until you find the heavier ball. Under this logic, the minimum number of weighings required turns out to be the smallest integer greater than or equal to log(n), where n is the total number of balls and the base of logarithm is 3. Or simply [log(n)/log(3)] with any base. Here, n = 6561. log 6561 / log 3 = 8 The answer is (B).

q: A 600 meter long train crosses a signal post in 40 seconds. How long will it take to cross a 3 kilometer long bridge, at the same speed?
Options:
(A) 2
(B) 3
(C) 4
(D) 1
(E) 8
a: Stream of consciousness: S = 600/40 = 15 mps
S = 3600/15 = 240 sec = 4 min The answer is (C).

question: A sells a bicycle to B at a profit of 20%. B sells it to C at a profit of 25%. If C pays Rs. 225 for it, the cost price of the bicycle for A is?
Options:
(A) 277
(B) 268
(C) 270
(D) 150
(E) 282
answer: Stream of consciousness: 125% of 120% of A = 225
125/100 * 120/100 * A = 225
A = 225 * 2/3 = 150. The answer is (D).

q: How many five-digit numbers satisfy this property.: The last digit (unit's digit) of the square of the two-digit number is 3 ?
Options:
(A) 33
(B) 66
(C) 0
(D) 99
(E) 132
a: Stream of consciousness: A number ending with 3 can never be a perfect square. The answer is (C).

q: Rs.800 amounts to Rs.920 in 3 years at simple interest. If the interest is increased by 3%, it would amount to how much?
Options:
(A) 3387
(B) 277
(C) 223
(D) 992
(E) 213
a:
Stream of consciousness: (800*3*3)/100 = 72
920 + 72 = 992 The answer is (D).