Ann and Joe’s father donated $3 for every lap they swam in a swim-a-thon. Ann swam 21 laps, and Joe swam 15 laps. Find the amount of money their father donated.

its adding 5.5 each time

step-by-step explanation:

answer:  

step-by-step explanation:

odd numbers are only divisible by 1 and itself.

even numbers are divisible by more than 1 and itself.

for example 6 is even because it is divisible by more than 1 and its self. 1 x 6= 6 ; 2 x 3= 6

and 7 is odd because only 7 x 1 equals seveb