I can’t figure this stuff out

The lines shown below are parallel. if the green line has a slope of -1, what is the slope of the red line?

Tom had a total of $220 and he spent $35 on a basketball ticket . what percent of his money did he have left?

At the beginning of 1974/75,2 years a man invested #2000 in a bank at 12.5% compound interest, if it degree #650 at the end of each two years to pay his son's school fees, after payment of interest to pay his son's school fees, how much did he have left at the beginning of the 1978/79 school year?