Question

kerry asked a bank teller to cash a $390 check using $20 bills and $50 bills. if the teller gave her a total of 15 bills, how many of eech type of bill did she recieve?

Answer 1

Let x = the number of $20 bills
Let y = the number of $50 bills
Then,
x + y = 15
Also, 20x + 50y = 390
Solving these two equations in two unknowns simultaneously,
x = 12 (number of $20 bills) and y = 3 (number of $50 bills)