Answer:
25
Step-by-step explanation:
because 25 times 2 is 50 and 25 times 3 is 75
hope I helped!!! ;)
There are 15 years was his money invested.
<h3>
What is simple interset?</h3>
Simple Interest is an easy method of calculating the interest for a loan/principal amount.
Given
Frank invests $1,000 in simple interest investment account that pays 8% a year.
After a number of years, he withdraws his balance of $2,200.
The number of years was his money inversted is;

Where p is the principal amount, r is the rate of interest, I is the amount and t is the time.
Substitute all the values in the formula;

Hence, in the 15 years was his money invested.
To know more about investing click the link given below.
brainly.com/question/26677076
Answer:
(3.10 x 10^10)
Step-by-step explanation:
Answer:
$420
Step-by-step explanation:
The formula for simple interest is i = prt, where p is the principal, r is the annual interest rate expressed as a decimal fraction, and t is the number of years.
Here p = $2,000, r = 0.07 and t = 3 yr, and so
i = ($2,000)(0.07)(3) = $420 was the amount of interest earned.