PSLE The airmail rates to two countries are shown. Shiyun sent a letter weighing 61g to Thailand and a letter weighing 21g to India by airmail. How much did she pay altogether?
Mass |
Thailand |
India |
First 30g |
$0.95 |
$1.50 |
Every additional 15g |
$0.75 |
$0.55 |
Mass of the letter to Thailand excluding the first 30 g
= 61 - 30
= 31 g
Sets of additional 15 g of the letter to Thailand
= 31 ÷ 15
= 2 r 1
Sets of additional 15 g and part thereof the letter to Thailand
= 2 + 1
= 3
Amount that Shiyun paid for the letter to Thailand
= 0.95 + 3 x 0.75
= 0.95 + 2.25
= $3.20
Amount that Shiyun paid altogether
= 3.20 + 1.50
= $4.70
Answer(s): $4.70