Question

Alejandro has 3 times as many $20 bills in his wallet as he has $5 bills. He also has twice as many $1 bills than $20 bills. If he has a total of $142 in his wallet, how much money does Alejandro have in $1 bills?

a)$2
b)$6
c)$10
d)$12

Answer 1

$12 in 12 $1 bills

Explanation:

Let the number of $1 bills be x.

Amount of money in $1 bills is $x.

Alejandro has twice as many $1 bills than $20 bills, then Alejandro has
`(x)/(2)` $20 bills.

Amount of money in $20 bills is
`\$ (x)/(2)\cdot 20.`

Alejandro has 3 times as many $20 bills in his wallet as he has $5 bills, then Alejandro has
`(x)/(2)/ 3=(x)/(6)` $5 bills.

Amount of money in $5 bills is
`\$(x)/(6)\cdot 5.`

If he has a total of $142 in his wallet, then

`x\cdot 1+(x)/(2)\cdot 20+(x)/(6)\cdot 5=142\\ \\x+10x+(5x)/(6)=142`

Multiply this equation by 6:

`6x+60x+5x=142\cdot 6\\ \\71x=852\\ \\x=12`