1.5 cm 1 30 cm 15 cm 20 cm Calculate the volume of the box using the external measurements.

So in 6 months (1/2yr) you earned $15.75 interest, if we double that we find the total interest you would gain for that year, 15.75x2= $31.5 total interest for that year.

To find the annual rate divide the interest gained by the amount deposited, 31.5/500 = 0.063% p.a.