Given:
Rate of simple interest = 5%
Time = 4 years
Total interest = $160
To find:
The amount borrowed by Austin from a credit union.
Solution:
The formula for simple interest is:

Where, P is principal, r is the rate of interest and t is the number of years.
Putting
in the above formula, we get



Multiply both sides by 5.

Therefore, Austin borrowed $800 from a credit union for 4 years.
That would simply be
38.14 ÷ 4 = 9.535
thus he scored 9.535 on each event
Anything that is inside the perenthasis are just like a regular math problem, so your answer should be:
C. 5