Question

A bank teller cashed a check for $200 using twenty dollar bills and ten dollar bills. In all, twelve bills werehanded to the customer. Find the number of twenty dollar bills and the number of ten dollar bills.

Answer 1

Number of $20 bills = 8

Number of $10 bills = 4

Step-by-step explanation:

Let x be the number of $20 bills.

Let y be the number of $10 bills.

From the question, we'll have the two equations below;

`\begin{gathered} 20x+10y=200 \\ x+y=12 \end{gathered}`

From the 2nd equation, y = 12 - x.

Let's put (y = 12 - x) into the 1st equation and slove for x;

`\begin{gathered} 20x+10(12-x)=200 \\ 20x+120-10x=200 \\ 10x=200-120 \\ x=(80)/(10) \\ \therefore x=8 \end{gathered}`

Since x = 8, let's substitute the value of x into (y = 12 - x) and find x;

`\begin{gathered} y=12-8 \\ \therefore y=4 \end{gathered}`