Q: For a particular American football game, the probability of a team's quarterback throwing a completed pass on each throw is 3/10. What is the least number of times that the quarterback should throw the ball that will increase the probability of getting a completed pass at least once to more than 50%.
Options:
(A) 10
(B) 5
(C) 2
(D) 3
(E) 1
A: OK... Stream of consciousness: Rule of Subtraction: P(A) = 1 - P(A')
Rule of Multiplication: P(A B) = P(A) P(B)
The probability that the quarterback throws a completed pass at least once in 2 throws is 1- (7/10)^2 = 1 - 49/100 = 51/100 > 50%
The answer is (C).

Q: If a man can cover 14 metres in one second, how many kilometres can he cover in 3 hours 45 minutes?
Options:
(A) 288
(B) 162
(C) 189
(D) 168
(E) 122
A: OK... Stream of consciousness: 14 m/s = 14 * 18/5 kmph
3 hours 45 minutes = 3 3/4 hours = 15/4 hours
Distance = speed * time = 14 * 18/5 * 15/4 km = 189 km.
The answer is (C).

Q: Which one of the following is not a prime number?
Options:
(A) 31
(B) 61
(C) 71
(D) 73
(E) 91
A: OK... Stream of consciousness: 91 is divisible by 7. So, it is not a prime number.
The answer is (D).

Q: The flow of water through a drainage pipe was monitored for a 3-hour period. In the second hour, the rate of flow was 12 gallons per hour, which was 50 percent faster than the rate of flow for the first hour. If 25 percent more water flowed through the pipe in the third hour than it did in the second, how many gallons of water flowed through the pipe during the entire three hours?
Options:
(A) 31.25
(B) 31.5
(C) 33.75
(D) 35.0
(E) 37.5
A:
OK... Stream of consciousness: Rate of flow of water in second hour = 12 gallons per hour
Rate of flow of water in first hour = 12/(3/2) = 8 gallons per hour
Rate of flow of water in third hour = (125/100)* 12 = (5/4) * 12 = 15 gallons per hour
Number of gallons of water that flowed through the pipe during the entire 3 hours = 12+8+15 = 35 gallons
The answer is (D).