A cashier has 25 bills consisting of twice as many ones as tens, two fewer fives than than ones, and the rest are twenties. If the total value is $140, find how many of each bill she has?

Answer 1

start writing the data as math.
Let the number of bills (1,5,10,20) be w,x,y,z. Then
w+x+y+z = 25
w = 2y
...
You will wind up with 4 equations to solve for w,x,y,z.