The table shows the airmail rates for sending letters and postcards to some countries.
Destination |
Letters |
Postcards |
|
Mass |
Postage Rate |
Per piece |
Thailand, Vietnam, Myanmar
|
1st 20 g |
$0.90 |
$0.90
|
Every additional 10 g or part thereof |
$0.45 |
How much did Usha pay for the postage when she sent a letter which weighed 67 g and 9 postcards to Myanmar by airmail?
Remaining mass that Usha had to pay for the letter as it was more than 20 g
= 67 - 20
= 47 g
Number of sets of additional 10 g of the letter that Usha had to pay for
= 47 ÷ 10
= 4 r 7
Total number of sets of additional 10 g of the letter that Usha had to pay for
= 4 + 1
= 5
Amount that Usha had to pay for the sets of additional 10 g of the letter
= 5 x 0.45
= $2.25
Total amount that Usha had to pay for the letter
= 0.90 + 2.25
= $3.15
Amount that Usha had to pay for the 9 postcards
= 9 x 0.90
= $8.10
Total amount that Usha paid
= 3.15 + 8.10
= $11.25
Answer(s): $11.25