Bobby wants to invest $100. His brother invested $2,000 for one year and earned $60 in simple interest.

Question

If Bobby invests his money for one year at the same interest rate as his brother, how much will he earn?

Answer 1

We can use proportions to solve this problem.

First, we need to find the interest rate that Bobby's brother earned:

$60 = 0.03 \times 2000

So the interest rate is 0.03 or 3%.

Now we can set up a proportion:

$60 is to $2,000 as X is to $100

This can be written as:

60/2000 = X/100

Simplifying, we get:

X = (60/2000) * 100 = $3

Therefore, if Bobby invests $100 for one year at the same interest rate as his brother, he will earn $3 in simple interest.