PSLE The airmail rates to two countries are shown. Lucy sent a letter weighing 98g to Thailand and a letter weighing 39g to Australia by airmail. How much did she pay altogether?
Mass |
Thailand |
Australia |
First 40g |
$0.65 |
$1.60 |
Every additional 20g |
$0.35 |
$0.60 |
Mass of the letter to Thailand excluding the first 40 g
= 98 - 40
= 58 g
Sets of additional 20 g of the letter to Thailand
= 58 ÷ 20
= 2 r 18
Sets of additional 20 g and part thereof the letter to Thailand
= 2 + 1
= 3
Amount that Lucy paid for the letter to Thailand
= 0.65 + 3 x 0.35
= 0.65 + 1.05
= $1.70
Amount that Lucy paid altogether
= 1.70 + 1.60
= $3.30
Answer(s): $3.30