The task is to generate the correct answer for a given math problem.

[EX Q]: Problem: at what rate percent on simple interest will rs . 750 amount to rs . 900 in 8 years ?
[EX A]: 2.5 %

[EX Q]: Problem: a can do a work in 15 days and b in 20 days . if they work on it together for 5 days , then the fraction of the work that is left is
[EX A]: 5 / 12

[EX Q]: Problem: tabby is training for a triathlon . she swims at a speed of 1 mile per hour . she runs at a speed of 7 miles per hour . she wants to figure out her average speed for these two events . what is the correct answer for her ?
[EX A]:
4 mph