She spent $310 on the singing camp.
MY WORK:
I multiplied $86.50*20 because $86.50 is the amount she deposited for 20 months. $86.50*20=$1740.00
Then I multiplied $24.50*20 because she spent $24.50 for 20 months. $24.50*20= $490.00
Then I subtracted $1740.00-$490.00 because she spent $490 out of her bank account. $1740.00-$490.00=$1240.00
Finally, because its 1/4 of her money, I divided $1240.00 by 4. $1240 divided by 4= $310
Hope this helps!!
:)