Joan invests $800 at 12.5% per anum compound intrest compounded daily. What is the amount of intrest at the end of first year?

A=P (1+i) ^n

P=800

i=0.125/12 (12.5/100 to get from percentage to normal and / 12 to convert from year to months)

n=12

A=800 (1+0.125/12) ^12

=905.93

Therefore, Interest = 905.93-800

=105.93