Problema Solution

A bank teller has 54 $5 and $20 bills in her cash drawer. The value of the

bills is $780. How many $5 bills are there?

Answer provided by our tutors

Let 5$ bills be x

$20 bills be y 

x+y=54 equation 1

5x+20y=780 equation 2

Put x=54-y in equation 2

5(54-y)+20y=780

270-5y+20y=780

15y=510

y=34

x=54-34 = 20 ANS