The formula to find the amount is
A = P(1+r)^n
P is the principal
r = rate of interest
n is the number of years
Here P = $10,000
r= 10% = 0.10
n = 3 years
Substituting the values in the formula we get
A= 10,000 (1 + 0.10)^3
A= 10,000(1.10)^3
A= $13,310
The compound interest earned during the three years = 13,310 - 10,000 = $3,310
John will have $13,310 after 3 years.