Because Jerrod missed a payment, the credit card company automatically raised the interest rate to 24%. How many years would it be until his balance doubles, assuming he continues to make no payments

A little over three years. If for instance, Jerrod's current balance is 1,000. Multiplying this figure by 1.24, four times will result to 2,364. So that's more than double. Hence, the answer is a little over 3 years until his balance doubles.