Question

Nina has $245 in 5-dollar bills and 10-dollar bills. She has ten more 5-dollar bills than 10-dollar bills. How many of each type of bill does she have?

Answer 1

Number of 5 dollar bills = 23

Number of 10 dollar bills = 13

Explanation:

Let number of 5 dollar bills be x

and the number of 10 dollar bills be y

Total $245, means we can write:

5x + 10y = 245

Ten more 5 dollar bills than 10 dollar bills, means:

x - 10 = y

Now we substitute 2nd equation in first and solve for x:

`5x + 10y = 245\\5x + 10(x-10) = 245\\5x+10x-100=245\\15x=345\\x=23`

Also,

y = x - 10

y = 23 - 10 = 13

So there are 23 5-dollar bills and 13 10-dollar bills