PSLE The airmail rates to two countries are shown. Shiyun sent a letter weighing 89g to Thailand and a letter weighing 39g to France by airmail. How much did she pay altogether?
Mass |
Thailand |
France |
First 40g |
$0.55 |
$1.30 |
Every additional 20g |
$0.25 |
$0.45 |
Mass of the letter to Thailand excluding the first 40 g
= 89 - 40
= 49 g
Sets of additional 20 g of the letter to Thailand
= 49 ÷ 20
= 2 r 9
Sets of additional 20 g and part thereof the letter to Thailand
= 2 + 1
= 3
Amount that Shiyun paid for the letter to Thailand
= 0.55 + 3 x 0.25
= 0.55 + 0.75
= $1.30
Amount that Shiyun paid altogether
= 1.30 + 1.30
= $2.60
Answer(s): $2.60