Will paid $30 for his shoes but then returned them and got 90% of the money back, so he lost 10% of the money, which means 10/100 * $30 = $<<10/100*30=3>>3 is gone.
Will spent $9 + $11 + $3 = $<<9+11+3=23>>23.
Will started with $74 - $23 that he spent = $<<74-23=51>>51 remaining.
#### 51