PSLE The airmail rates to two countries are shown. Gwen sent a letter weighing 66g to Laos and a letter weighing 15g to India by airmail. How much did she pay altogether?
Mass |
Laos |
India |
First 20g |
$0.55 |
$1.40 |
Every additional 10g |
$0.35 |
$0.50 |
Mass of the letter to Laos excluding the first 20 g
= 66 - 20
= 46 g
Sets of additional 10 g of the letter to Laos
= 46 ÷ 10
= 4 r 6
Sets of additional 10 g and part thereof the letter to Laos
= 4 + 1
= 5
Amount that Gwen paid for the letter to Laos
= 0.55 + 5 x 0.35
= 0.55 + 1.75
= $2.30
Amount that Gwen paid altogether
= 2.30 + 1.40
= $3.70
Answer(s): $3.70