Question

The freshman class treasury has 30 ten and rwenty dollar bills that have a total value of 430. How many of each bill do they have??

Answer 1

The freshman class treasury has 30 ten and twenty-dollar bills that have a total value of 430. How many of each bill do they have??

Let

x -----> number of ten dollar bills

y -----> number of twenty dollar bills

we have

x+y=30 -----> x=30-y -----> equation 1

and

10x+20y=430 -----> equation 2

solve the system

substitute equation 1 in equation 2

10(30-y)+20y=430

solve for y

300-10y+20y=430

10y=430-300

10y=130

y=13

Find the value of x

x=30-13

x=17

therefore

17 ten dollar bills and 13 twenty dollar bills