The table shows the airmail rates for sending letters and postcards to some countries.

Destination	Letters		Postcards
	Mass	Postage Rate	Per piece
Korea, Japan	1st 40 g	$0.90	$0.60
	Every additional 10 g or part thereof	$0.45

How much did Yoko pay for the postage when she sent a letter which weighed 69 g and 2 postcards to Korea by airmail?
Remaining mass that Yoko had to pay for the letter as it was more than 40 g
= 69 - 40
= 29 g

Number of sets of additional 10 g of the letter that Yoko had to pay for 
= 29 ÷ 10
= 2 r 9

Total number of sets of additional 10 g of the letter that Yoko had to pay for 
= 2 + 1
= 3

Amount that Yoko had to pay for the sets of additional 10 g of the letter
= 3 x 0.45
= $1.35

Total amount that Yoko had to pay for the letter
= 0.90 + 1.35
= $2.25

Amount that Yoko had to pay for the 2 postcards
= 2 x 0.60
= $1.20

Total amount that Yoko paid
= 2.25 + 1.20
= $3.45

Answer(s): $3.45