Sales=$720 comission rate=5% commission= ?

$36

Step-by-step explanation:

a) we are looking for 5% of $720 or looking for how much commission was already taken which also means 5% of $720. Answer a = $36

as 10% = $72 and  5% = 72/2 = $36

b) If the question says what was the original amount if 5% the commission was taken already. Here we do answer b) = 105% of 720 =756  756-720 5% = 36 and we already found the answer to be $756 if being asked for an original sum.