Is 20 mm equal to 2 cm

What aspects of lines have to be diffrent

Trish receives $450 on the first of each month. josh receives $450 on the last day of each month. both trish and josh will receive payments for next four years. at a discount rate of 9.5 percent, what is the difference in the present value of these two sets of payments?

Can someone pls ! pls answer all. no explanation needed..