q: How much is 80% of 40 is greater than 4/5 of 25?
Options:
(A) 17
(B) 19
(C) 11
(D) 12
(E) 10
a: OK... (80/100) * 40 (4/5) * 25
32 - 20 = 12
The answer is (D).

q: The average age of applicants for a new job is 30, with a standard deviation of 8. The hiring manager is only willing to accept applicants whose age is within one standard deviation of the average age. Assuming that all applicants' ages are integers and that the endpoints of the range are included, what is the maximum number of different ages of the applicants?
Options:
(A) 8
(B) 16
(C) 17
(D) 18
(E) 34
a: OK... Minimum age = Average - 1 Standard deviation = 30 - 8 = 22
Maximum age = average + 1 Standard deviation = 30+ 8 = 38
Maximum number of different ages of the applicants = 38 - 22 + 1 = 17
The answer is (C).

q: Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 4 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) 120 gallons
(D) 160 gallons
(E) 130 gallons
a:
OK... Work done by the waste pipe in 1 minute = 1/15 - (1/20 + 1/24) = - 1/40
Volume of 1/40 part = 4 gallonsVolume of whole = 4 * 40 = 160 gallons.
The answer is (D).