Simple interest formula:
i = Prt
where
i = interest earned
P = principal amount invested
r = interest rate
t = time
In this problem, we are looking for i.
P = $10,000
r = 3.5% = 0.035
t = 7 years
i = Prt
i = $10,000 * 0.035 * 7 = $2,450
The amount of interest earned in the 7 years is $2,450.
The interest is added to the principal amount that was invested, so after 7 years, David has $10,000 + $2,450 = $12,450
Answer: Choice H.