q: Find the value of y from (12)^3 x 6^4 ÷ 432 = y?
Options:
(A) 3456
(B) 4567
(C) 4789
(D) 5678
(E) 5184
a: OK... Given Exp. = (12)3 x 64 = (12)3 x 64 = (12)2 x 62 = (72)2 = 5184
432 12 x 62
The answer is (E).

q: Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 1 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is?
Options:
(A) 40 gallons
(B) 100 gallons
(C) 120 gallons
(D) 180 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 = 1 gallons\
Volume of whole = 1 * 40 = 40 gallons.
The answer is (A).

q: The speed of a boat in still water is 60kmph and the speed of the current is 10kmph. Find the speed downstream and upstream?
Options:
(A) 40, 68 kmph
(B) 70, 50 kmph
(C) 90, 60 kmph
(D) 40, 60 kmph
(E) 20, 60 kmph
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
OK... Speed downstream = 60 + 10 = 70 kmph
Speed upstream = 60 - 10 = 50 kmph
The answer is (B).