PSLE The airmail rates to two countries are shown. Penelope sent a letter weighing 57g to Thailand and a letter weighing 19g to Egypt by airmail. How much did she pay altogether?
Mass |
Thailand |
Egypt |
First 20g |
$0.65 |
$1.10 |
Every additional 10g |
$0.25 |
$0.45 |
Mass of the letter to Thailand excluding the first 20 g
= 57 - 20
= 37 g
Sets of additional 10 g of the letter to Thailand
= 37 ÷ 10
= 3 r 7
Sets of additional 10 g and part thereof the letter to Thailand
= 3 + 1
= 4
Amount that Penelope paid for the letter to Thailand
= 0.65 + 4 x 0.25
= 0.65 + 1.00
= $1.65
Amount that Penelope paid altogether
= 1.65 + 1.10
= $2.75
Answer(s): $2.75