PSLE The airmail rates to two countries are shown. Penelope sent a letter weighing 51g to Malaysia and a letter weighing 18g to Australia by airmail. How much did she pay altogether?
Mass |
Malaysia |
Australia |
First 20g |
$0.85 |
$1.70 |
Every additional 10g |
$0.45 |
$0.75 |
Mass of the letter to Malaysia excluding the first 20 g
= 51 - 20
= 31 g
Sets of additional 10 g of the letter to Malaysia
= 31 ÷ 10
= 3 r 1
Sets of additional 10 g and part thereof the letter to Malaysia
= 3 + 1
= 4
Amount that Penelope paid for the letter to Malaysia
= 0.85 + 4 x 0.45
= 0.85 + 1.80
= $2.65
Amount that Penelope paid altogether
= 2.65 + 1.70
= $4.35
Answer(s): $4.35