PSLE The airmail rates to two countries are shown. Eva sent a letter weighing 89g to Thailand and a letter weighing 34g to New Zealand by airmail. How much did she pay altogether?
Mass |
Thailand |
New Zealand |
First 40g |
$0.75 |
$1.50 |
Every additional 20g |
$0.55 |
$0.55 |
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 Eva paid for the letter to Thailand
= 0.75 + 3 x 0.55
= 0.75 + 1.65
= $2.40
Amount that Eva paid altogether
= 2.40 + 1.50
= $3.90
Answer(s): $3.90