TASK DEFINITION: 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.
PROBLEM: Problem: what is the rate percent when the simple interest on rs. 810 amount to rs. 155 in 4 years ?
Options: a. 4.78, b. 4.68, c. 4.58, d. 4.48, e. 4.38

SOLUTION: a

PROBLEM: Problem: two trains are moving in opposite directions at 60 km / hr and 90 km / hr. their lengths are 1.15 km and 0.6 km respectively. the time taken by the slower train to cross the faster train in seconds is ?
Options: a. 42, b. 9, c. 7, d. 67, e. 15

SOLUTION: a

PROBLEM: Problem: a rectangle having length 105 cm and width 40 cm. if the length of the rectangle is increased by twenty five percent then how much percent the breadth should be decreased so as to maintain the same area.
Options: a. 25 %, b. 19.23 %, c. 40 %, d. 75 %, e. none of these

SOLUTION:
b