Work backwards from the $60 Amy had left.<br><br>
[[model:questions/solutions/q10425.png]]<br><br>
Before lunch, Amy had: $60 + $12 = $72<br>
&bull; $72 is 60% of the remainder after the dress (since 40% was spent on shoes).<br>
&bull; Remainder after dress = $72 ÷ 60 × 100 = $72 ÷ 0.6 = $120<br>
&bull; Amy started with $240, so the dress cost = $240 − $120 = $120<br><br>
The dress cost $120.<br>
Check: $240 − $120 = $120; 40% of $120 = $48 (shoes); $120 − $48 = $72; $72 − $12 = $60. ✓