Math
posted by darryl .
an envelope contains 20 bills in denominations of $1,$5,$10, there are two times as many $5 bills as there are$10 bills. the total of the envelope is $54. how many of each bill do i have

let number of tens be x
then number of fives = 2x
number of ones = 20  3x
10x + 5(2x) + 1(203x) = 54
solve for x, sub back into my definitions
(should get 2 tens, 4 fives, and 14 ones)