How many $10 bills and $20 bills equal $450

Question

Part of the proceeds from a garage sale was $450 worth of $10 and $20 dollar bills. If there were 3 more $10 bills than $20 bills, find the number of each denomination.

Answer 1

Let X be the number of $10 bills (as X is the roman numeral for 10)

and J by the number of $20 bills (as Andrew JACKSON is on the $20)

 

X = J + 3

 

10X + 20J = 450

 

10(J+3) + 20J = 450

10J + 30 + 20J = 450

 

30J + 30 = 450

 

30J = 420

 

J = 420/30 = 42/3 = 14

 

There are 14 x $20 and 17 x $10, which is $280 + 170 = $450