Question

A person invested $ 7,200 in an account growing at a rate allowing the money to double every 13 years. How long, to the nearest tenth of a year would it take for the value of the account to reach $25,200?

Answer 1

To find the amount of time it takes for an investment to double, we can use the rule of 70. In this case, it would take approximately 46.7 years for the value of the account to reach $25,200.

Step-by-step explanation:

To find the amount of time it takes for an investment to double, we can use the rule of 70.

The rule of 70 states that to find the number of years it takes for an investment to double, divide 70 by the interest rate.

In this case, the interest rate is 100% (since the money doubles) and the time it takes is 13 years.

So, to find how long it would take for $7,200 to reach $25,200, we can use the rule of 70.

The interest rate would be 100% (since the money doubles) and the initial amount is $7,200.

We want to find the time it takes to reach $25,200, so let's call that T.

70 / 100 = $25,200 / $7,200 = T

Dividing both sides of the equation by 150 gives:

T = 46.67

So, it would take approximately 46.7 years for the value of the account to reach $25,200.