q: How much more would Rs.10000 fetch, after two years, if it is put at 20% p.a. compound interest payable half yearly than if is put at 20% p.a. compound interest payable yearly?
Options:
(A) 241
(B) 725
(C) 992
(D) 837
(E) 923
a: Stream of consciousness: 10000(11/10)4 - 10000(6/5)2 = 241 The answer is (A).

question: The price of a T.V. set worth Rs. 8000 is to be paid in 20 installments of Rs. 750 each. If the rate of interest be 6% per annum, and the first installment be paid at the time of purchase, then the value of the last installment covering the interest as well will be?
Options:
(A) 7250
(B) 7200
(C) 7820
(D) 6000
(E) 2799
answer: Stream of consciousness: Money paid in cash = Rs. 750
Balance payment = (8000- 1000) = Rs. 7250 The answer is (A).

q: Ravi can do a piece of work in 20 days while Prakash can do it in 40 days. In how many days will they finish it together?
Options:
(A) 5 7/9 days
(B) 6 7/9 days
(C) 5 1/9 days
(D) 5 7/2 days
(E) 4 7/9 days
a: Stream of consciousness: 1/20 + 1/40 = 3/40
40/7 = 5 7/9 days The answer is (A).

question: How many seconds will a train 100 meters long take to cross a bridge 150 meters long if the speed of the train is 36 kmph?
Options:
(A) 22 sec
(B) 77 sec
(C) 25 sec
(D) 18 sec
(E) 17 sec
answer: Stream of consciousness: D = 100 + 150 = 250
S = 36 * 5/18 = 10 mps
T = 250/10 = 25 se The answer is (C).

q: Grace has 18 jellybeans in her pocket. She has 9 red ones, 5 green ones, and 4 blue ones. What is the minimum number of jellybeans she must take out of her pocket to ensure that she has one of each color?
Options:
(A) 4
(B) 8
(C) 12
(D) 13
(E) 15
a: Stream of consciousness: The worst scenario is when she takes 9 red and 5 green, total of 14 jellybeans, and still doesn't have 3 distinct colors. But the next draw (15th) will surely be the third color jellybean (blue) as there is no other color jellybeans left in pocket. The answer is (E).

q: If X is the sum of first 20 positive even integers and Y is the sum of first 20 positive odd integers, what is the value of x-y?
Please try to explain your answers
Options:
(A) 0
(B) 20
(C) 50
(D) 75
(E) 100
a:
Stream of consciousness: First even minus first odd = 2-1 = 1;
The sum of first 2 even integers minus the sum of first 2 odd integers = (2+4)-(1+3) = 2;
The sum of first 3 even integers minus the sum of first 3 odd integers = (2+4+6)-(1+3+5) = 3;
We can see the patterns here, so the sum of first 20 positive even integers minus the sum of first 20 positive odd integers will be 20. The answer is (B).