PSLE The airmail rates to two countries are shown. Linda sent a letter weighing 81g to Thailand and a letter weighing 30g to Egypt by airmail. How much did she pay altogether?
Mass |
Thailand |
Egypt |
First 40g |
$0.85 |
$1.20 |
Every additional 20g |
$0.55 |
$0.40 |
Mass of the letter to Thailand excluding the first 40 g
= 81 - 40
= 41 g
Sets of additional 20 g of the letter to Thailand
= 41 ÷ 20
= 2 r 1
Sets of additional 20 g and part thereof the letter to Thailand
= 2 + 1
= 3
Amount that Linda paid for the letter to Thailand
= 0.85 + 3 x 0.55
= 0.85 + 1.65
= $2.50
Amount that Linda paid altogether
= 2.50 + 1.20
= $3.70
Answer(s): $3.70