PSLE The airmail rates to two countries are shown. Lynn sent a letter weighing 90g to Phillippines and a letter weighing 38g to New Zealand by airmail. How much did she pay altogether?
Mass |
Phillippines |
New Zealand |
First 40g |
$0.85 |
$1.80 |
Every additional 20g |
$0.55 |
$0.70 |
Mass of the letter to Phillippines excluding the first 40 g
= 90 - 40
= 50 g
Sets of additional 20 g of the letter to Phillippines
= 50 ÷ 20
= 2 r 10
Sets of additional 20 g and part thereof the letter to Phillippines
= 2 + 1
= 3
Amount that Lynn paid for the letter to Phillippines
= 0.85 + 3 x 0.55
= 0.85 + 1.65
= $2.50
Amount that Lynn paid altogether
= 2.50 + 1.80
= $4.30
Answer(s): $4.30