PSLE The airmail rates to two countries are shown. Yen sent a letter weighing 81g to Thailand and a letter weighing 29g to Canada by airmail. How much did she pay altogether?
Mass |
Thailand |
Canada |
First 30g |
$0.85 |
$1.20 |
Every additional 15g |
$0.55 |
$0.40 |
Mass of the letter to Thailand excluding the first 30 g
= 81 - 30
= 51 g
Sets of additional 15 g of the letter to Thailand
= 51 ÷ 15
= 3 r 6
Sets of additional 15 g and part thereof the letter to Thailand
= 3 + 1
= 4
Amount that Yen paid for the letter to Thailand
= 0.85 + 4 x 0.55
= 0.85 + 2.20
= $3.05
Amount that Yen paid altogether
= 3.05 + 1.20
= $4.25
Answer(s): $4.25