Pre Calculus Investment Interest

Question

How long will it take for $5,000 to double in the following investments? round to the nearest tenth of a year. (as we saw within a month is normally sufficient in these problems)

Simple interest earning 7.4%APR: 

years.Compounded monthly earning 7.4%APR: 

years.compounded continuously earning 7.4%APR: 

years.How much money would be in the account after 10 years for each of the following investments. Round to the cent.

Simple interest earning 7.4%APR: $

.Compounded monthly earning 7.4%APR: $

.Compounded continuously earning 7.4%APR: $

.

Answer 1

2 = 0.074t

2 = (1 + 0.075/12)^12t

2 = e^0.074t