Leila, Scott, and Chau served a total of 90 orders Monday at the school cafeteria. Leila served 10 more orders than Scott. Chau served 2 times as many orders as Scott. How many orders did they each serve?

L + S + C = 90

L = S + 10

C = 2S

S + 10 + S + 2S = 90

4S + 10 = 90

4S = 90 - 10

4S = 80

S = 80/4

S = 20 < = = = Scott served 20

L = S + 10

L = 20 + 10

L = 30 < = = Leila served 30

C = 2S

C = 2 (20)

C = 40 < = = Chau served 40