TASK DEFINITION: You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.
PROBLEM: Question: The number of diagonals of a polygon of n sides is given by the formula z=n(n-3)/2. If a polygon has twice as many diagonals as sides, how many sides does it have?

Option A: 3

Option B: 5

Option C: 6

Option D: 7

Option E: 8

SOLUTION: Option B

PROBLEM: Question: There are 36 students in a certain geometry class. If one third of the students are boys and one fourth of the boys are under six feet tall, how many boys in the class are under six feet tall?

Option A: 3

Option B: 12

Option C: 18

Option D: 24

Option E: 27

SOLUTION: Option A

PROBLEM: Question: The perimeter of a triangle is 40 cm and the inradius of the triangle is 2.5 cm. What is the area of the triangle?

Option A: 76 cm2

Option B: 56 cm2

Option C: 18 cm2

Option D: 98 cm2

Option E: 50 cm2

SOLUTION:
Option E