Answer:
about 3 years
Explanation:
Using the compound interest formula;
A = P(1+r)^t
Given
Amount A == $2400
Principal P = $1200
rate = 24.77% = 0.2477
Substitute the given values
2400 = 1200(1+0.2477)^t
2400/1200 = (1+0.2477)^t
2 = (1+0.2477)^t
ln 2 = tln1.2477
t = ln2/ln1.2477
t = 3.13
Hence it will take about 3 years until Brad owes the credit card company $2,400