Problema Solution
A wallet contains $460 in $5, $10, and $20 bills.The number of $5 bills exceeds twice the number of $10 bills by 4, and the number of $20 bills is 6 fewer than the number of $10 bills.
How many $10?
Answer provided by our tutors
let
x = the number of $5 bills
y = the number of $10 bills
z = the number of $20 bills
A wallet contains $460
5x + 10y + 20z = 460
the number of $5 bills exceeds twice the number of $10 bills by 4
x = 2y + 4
the number of $20 bills is 6 fewer than the number of $10 bills
z = y - 6
plug x = 2y + 4 and z = y - 6 into 5x + 10y + 20z = 460 and we get
5(2y + 4) + 10y + 20(y - 6) = 460
by solving we find
y = 14 bills
click here to see the step by step solution of the equation
there are fourteen $10 bills.