I am bored out my mind

Determine the fraction of total interest owed. after the fourth month of a 12-month loan: the numerator is: {(n + ) + (n + ) + (n + ) + (n + )} = , and the denominator is: {(n) + (n + 1) + + (n + )} = . therefore, the fraction is numerator/denominator (to the nearest tenth) =

9/10 divide by -3/15 as a mixed number

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25