Ai Tong School P5 Math CA1 2006 (Q43)

Mrs Li had $10 more than Mrs Devi. Mrs Li spent all her money on 12 plates while Mrs Devi used all her money to buy 8 cups at $1.65 each and 4 plates. Find the cost of 1 plate.

Solution



Adding both Li’s and Devi’s items and cost, we get

2 units + $10 ----- 12 plates + 4 plates + 8 cups

2 units ----- 16 plates + (8 cups x $1.65) - $10

2 units ----- 16 plates + $13.20 - $10

2 units ----- 16 plates + $3.20

1 unit ----- (16 plates + $3.20) divided by 2

1 unit ----- 8 plates + $1.60


(Li) 1 unit + $10 ----- 12 plates

8 plates + $1.60 + $10 ----- 12 plates

$11.60 ----- 12 plates – 8 plates

$11.60 ----- 4 plates

1 plate ----- $11.60 divided by 4 = $2.90

Answer: One plate cost $2.90.