q: Two trains are traveling on parallel tracks in the same direction. The faster train travels at 130 miles per hour, while the slower train travels at 100 miles per hour. At 2 o’clock the faster train is 5 miles behind the slower one. How far apart are the two trains at 5 o'clock?
Options:
(A) 60 miles
(B) 80 miles
(C) 90 miles
(D) 120 miles
(E) 85 miles
a: OK... Answer = E. 85 miles
Relational speed = 130 - 100 = 30 miles per hour
In 3 hours, difference = 30 * 3 = 90 miles
Fast train trailing 5 miles, so effective difference = 90 - 5 = 85 miles
The answer is (E).

q: If 10 men can reap 120 acres of land in 15 days, how many acres of land can 20 men reap in 30 days?
Options:
(A) 120
(B) 240
(C) 360
(D) 1200
(E) 480
a: OK... 10 men 120 acres 15 days
20 men ? 30 days
120 * 20/10 * 30/15
120 *2 * 2
120 * 4 = 480
The answer is (E).

q: The speed of a boat in still water is 50kmph and the speed of the current is 20kmph. Find the speed and upstream?
Options:
(A) 30 kmph
(B) 40 kmph
(C) 78 kmph
(D) 15 kmph
(E) 23 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 = 50 + 20 = 70 kmph
Speed upstream = 50 - 20 = 30 kmph
The answer is (A).