John invested $400 in a savings account. How much interest will he earn on 5 years if the interest rate is 7%?

Amount Invested by John in the savings account = $400

Rate of interest = 7%

Time period for which the money is kept = 5 years

Now the formula for calculating the amount of interest is

I = P * R * T

where

I = Interest Amount

P = Principal Amount

R = rate of Interest

T = Time for which the money is kept

Now we know all the details within the formula, and so calculating the interest amount is easy.

I = P * R * T

= 400 * (7/100) * 5

= 400 *.07 * 5

= 2000 *.07

= 140

So the amount of interest that John will gain after 5 years is $140.