Amount of money that Mr Leong won in the lucky draw was $480
Cost of wallet = 1/3x$480+$20 = $180
Amount of money left after spending on wallet= $(480-180) = $300
Cost of treat for family = 3/5x$300+$30 = $210
Amount of money left after spending on wallet and treat = $480-$180-$210= $90
Amount of money left after spending on shirt = $18
Cost of shirt = $90-$18=$72
Difference between cost of shirt and treat = $210-$72 = $138
This is an interesting question.Is this from your P6 Prelim exam question or just P6 Prelim practice paper?