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 40 g |
$0.90 |
$0.90
|
Every additional 10 g or part thereof |
$0.40 |
How much did Opal pay for the postage when she sent a letter which weighed 113 g and 8 postcards to Myanmar by airmail?
Remaining mass that Opal had to pay for the letter as it was more than 40 g
= 113 - 40
= 73 g
Number of sets of additional 10 g of the letter that Opal had to pay for
= 73 ÷ 10
= 7 r 3
Total number of sets of additional 10 g of the letter that Opal had to pay for
= 7 + 1
= 8
Amount that Opal had to pay for the sets of additional 10 g of the letter
= 8 x 0.40
= $3.20
Total amount that Opal had to pay for the letter
= 0.90 + 3.20
= $4.10
Amount that Opal had to pay for the 8 postcards
= 8 x 0.90
= $7.20
Total amount that Opal paid
= 4.10 + 7.20
= $11.30
Answer(s): $11.30