I can't figure this out

Che Maplewood Supply received a $5,340 invoice dated April 15, 2015. The $5 140 included $340 freight. Terms were 4/10, 3/30, n/60. (If more than one discount, assume date of last discount ) a. If Maplewood pays the invoice on April 27, what will it pay? Payable amount b. If Maplewood pays the invoice on May 21, what will it pay? Payable amount