PSLE The airmail rates to two countries are shown. Risa sent a letter weighing 66g to Phillippines and a letter weighing 13g to Egypt by airmail. How much did she pay altogether?
Mass |
Phillippines |
Egypt |
First 20g |
$0.75 |
$1.50 |
Every additional 10g |
$0.45 |
$0.55 |
Mass of the letter to Phillippines excluding the first 20 g
= 66 - 20
= 46 g
Sets of additional 10 g of the letter to Phillippines
= 46 ÷ 10
= 4 r 6
Sets of additional 10 g and part thereof the letter to Phillippines
= 4 + 1
= 5
Amount that Risa paid for the letter to Phillippines
= 0.75 + 5 x 0.45
= 0.75 + 2.25
= $3.00
Amount that Risa paid altogether
= 3.00 + 1.50
= $4.50
Answer(s): $4.50