Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

[EX Q]: Problem: you have been given a physical balance and 7 weights of 40, 42, 36, 33, 47, 52 and 67 kgs. keeping weights on one pan and object on the other, what is the maximum you can weigh less than 169 kgs.
Options: a. 163, b. 166, c. 162, d. 164, e. 165
[EX A]: e

[EX Q]: Problem: 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 ?
Options: a. 87 cm 2, b. 28 cm 2, c. 98 cm 2, d. 26 cm 2, e. 50 cm 2
[EX A]: e

[EX Q]: Problem: the area of a triangle is with base 4 m and height 6 m ?
Options: a. 11 m 2, b. 10 m 2, c. 18 m 2, d. 19 m 2, e. 12 m 2
[EX A]:
e