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April 30, 2016

# Homework Help: Pre Calculus

Posted by Jona on Tuesday, February 19, 2013 at 6:38pm.

A bank teller is counting the total amount of money in a cash register at the end of the day. There is a total of \$2600 in denominations of \$1, \$5, \$10 and \$20 dollar bills.

The total number of paper bills is \$235. The number of twenty dollar bills is twice the number of \$1 dollar bills and the number of \$5 dollar bills is ten more than the number of \$1 dollar bills. What is the system of equations to repersent the situation. Then use matrices to find the number of bills for each denomination.
• Pre Calculus - Henry, Wednesday, February 20, 2013 at 9:29pm

X \$1 Bills.
2x \$20 Bills.
(X+10) \$5 Bills.
Y \$10 Bills.

x + 2x + (x+10) + y = 235
4x + 10 + y = 235
Eq1: 4x + y = 225.

1*x + 20*2x + 5(x+10) + 10y = \$2600.
46x+50+10y = 2600.
Eq2: 46x+10y = 2550

-40x - 10y = -2250
46x + 10y = 2550
6x = 300.
X = 50.
2X = 100
X+10 = 60

4*50 + y = 225
Y = 25.

The student should solve Eq1 and Eq2 using matrix and get the same results.