Rationale: Increase = (20/50)*100 = (2/5)*100 = 40%.
The answer: (E)
Question: John makes $50 a week from his job. He earns a raise and now makes $70 a week. What is the % increase?
Options:
(A) 16%
(B) 16.66%
(C) 17.9%
(D) 20%
(E) 40%

Rationale: 360/10 = 36. The difference is 36 - 30 = 6.
The answer: (C)
Question: A certain car uses 12 gallons of gasoline in traveling 360 miles. In order for the car to travel the same distance using 10 gallons of gasoline, by how many miles per gallon must the car's gas mileage be increased?
Options:
(A) 2
(B) 4
(C) 6
(D) 8
(E) 10

Rationale: (average) = (perimeter)/3;
12 = (perimeter)/3;
(perimeter) = 36.
The answer: (E)
Question: The average length of the sides of triangle ABC is 12. What is the perimeter of triangle ABC?
Options:
(A) 4
(B) 6
(C) 12
(D) 24
(E) 36