Answer:
You have to invest $6,250
Step-by-step explanation:
very simple applying the simple interest formula which is

Given data
A, final amount
= $10,000
P, initial principal balance= ?
r, annual interest rate
= 7.5%
t, time (in years)= 8 years
we can substitute our given data to find the principal needed.

Divide both sides by 1.6 we have

P= $6,250