EXPLANATION:
Let the no. of orders Greg served be x.
Orders Chau served = 2x
Orders Maya served= x + 9
Orders served in all= 69
x + 2x + x + 9 = 69
=> 4x + 9 = 69
=> 4x = 69 - 9
=> x = 60/4
=> x = 15
ANSWER:
Number of orders Maya served = (15 + 9) 24
Number of orders Greg served = 15
Number of orders Chau served = (2*15) 30
Hope it helps u!
