SOLUTION: in his wallet Jason has twice as many $5 bills as $20 dollar bills. If the total value of the bill is $90 then how many $5 bills are in his wallet? I tried: 2x = $5 bills x

Algebra ->  Customizable Word Problem Solvers  -> Finance -> SOLUTION: in his wallet Jason has twice as many $5 bills as $20 dollar bills. If the total value of the bill is $90 then how many $5 bills are in his wallet? I tried: 2x = $5 bills x       Log On

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Question 594144: in his wallet Jason has twice as many $5 bills as $20 dollar bills. If the total value of the bill is $90 then how many $5 bills are in his wallet?
I tried:
2x = $5 bills
x = $20 bills
2x + x = $90
3x = 90
x = 30
Therefore there are 60 $5 bills. This is incorrect.

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
The error lies in the equation 2x+%2B+x+=+90

You have x $20 bills, so in total, you have 20x dollars (NOT x dollars) in twenties

Similarly, you have 2x $5 bills, so you have 5*(2x) = 10x dollars in fives.

Add them up to get

20x + 10x = 30x


So this means that the equation is really

30x = 90

Solve for x:

30x = 90

x = 90/30

x = 3

So you have 3 $20 bills and 2*3 = 6 $5 bills


Check:

You have 3 $20 bills, so you have 3*20 = $60

You also have 6 $5 bills, so you add on 6*5 = $30

In total, you have $60 + $30 = $90.

So the answer checks out.