q: There are 8 books in a shelf that consist of 1 paperback books and 7 hardback books. If 4 books are selected at random without replacement, how many different combinations are there that at least one paperback book is selected?
Options:
(A) 35
(B) 45
(C) 50
(D) 55
(E) 60
a: Stream of consciousness: 8C4 [Select any four] - 7C4 [Select all hard backs] = 35. The answer is (A).


question: 4000 was divided into two parts such a way that when first part was invested at 3% and the second at 5%, the whole annual interest from both the investments is Rs.144, how much was put at 3%?
Options:
(A) 3377
(B) 2678
(C) 2800
(D) 2786
(E) 1981
answer: Stream of consciousness: (x*3*1)/100 + [(4000 - x)*5*1]/100 = 144
3x/100 + 200 – 5x/100 = 144
2x/100 = 56 è x = 2800' The answer is (C).


q: How many two-digit numbers satisfy this property.: The last digit (unit's digit) of the square of the two-digit number is 8 ?
Options:
(A) 1
(B) 2
(C) 3
(D) 4
(E) none of these
a: Stream of consciousness: A number ending in 8 can never be a perfect squar The answer is (E).


question: Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 6 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is?
Options:
(A) 60 gallons
(B) 100 gallons
(C) 240 gallons
(D) 180 gallons
(E) 130 gallons
answer: Stream of consciousness: Work done by the waste pipe in 1 minute = 1/15 - (1/20 + 1/24) = - 1/40
Volume of 1/40 part = 6 gallons\
Volume of whole = 6 * 40 = 240 gallons. The answer is (C).


q: A no.when divided by 125 gives a remainder 40, what remainder will be obtainedby dividingthe same no.15?
Options:
(A) 10
(B) 11
(C) 12
(D) 13
(E) 14
a: Stream of consciousness: 125 + 40 = 165/15 = 11 (Remainder) The answer is (B).


q: A train running at the speed of 60 km/hr crosses a pole in 9 seconds. Find the length of the train?
Options:
(A) 150
(B) 277
(C) 299
(D) 662
(E) 181
a:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Stream of consciousness: Speed = 60*(5/18) m/sec = 50/3 m/sec
Length of Train (Distance) = Speed * Time
(50/3) * 9 = 150 meter The answer is (A).