Formula calculate the comission according some condition

Formula calculate the comission according some condition

example
salesman achieve 4.5 box and 1 carton in a month.
16box become 1 carton
(4.5/16)+1 = 1.28 carton

help me make a fromula can calculate as below:
total carton 1.28, it on the range 1 box RM6 , 1 carton RM9.
(box) 4.5 x 6 = 27
(carton) 1 x 90 = 90

total comission RM117

Please refer to attachment, thks

Reputation sure to be given for appreciate your helpful