Question

Roberto is charged 0.04% compound interest per day on his credit card purchase of $1200. Find the amount of interest owning after 30 days.

Answer 1

Given:

Assuming 360days in a year and proceeding

$P=\text{ \ 1200 ; r=0.04\% ; }t=\frac{1}{12}\text{ years ; n=36}0$$A=P(1+\frac{r}{n})^{nt}$$A=1200(1+\frac{0.04}{360})^{360\times\frac{1}{12}}$$A=1200(1.0001)^{30}$$A=1200(1.003)$$A=1203.60$

Amount of interest owning after 30days is $3.60