Sanjay borrowed 7,000 at a simple interest rate of 3% per year. After a certain number of years he had paid $840 in interest altogether. How many years was that?

It was 4 years.

Step-by-step explanation:

To solve this problem we need to use the appropriate formula for simple interest, which is shown below:

M = C*r*t

Where M is the amount of interest, C is the initial amount of money, r is the rate of interest and t is the time elapsed in years. Applying the data from the problem we have:

840 = 7000*0.03*t

840 = 210*t

210*t = 840

t = 840/210

t = 4

It was 4 years.