Nick spent $918 on shirts and skirts. The number of skirts he bought was ¹₃ the number of shirts he bought. The cost of a skirt was $9 more than the cost of a shirt. He paid $378 more on shirts than on skirts. Find the cost of 7 shirts and 10 skirts.

	Shirts	Skirts
Number of sets	3 sets	1 set
Compare each		$9 more
Total value	$648	$270

Total cost of skirts
= (918 - 378) ÷ 2
= $270

Total cost of shirts
= 270 + 378
= $648

3 sets of shirts = $648
1 set of shirts = 648 ÷ 3 = $216 

1 set of skirts = $270

Difference in 1 set of skirts and 1 set of shirts
= 270 - 216
= $54

Number of clothing in 1 set
= 54 ÷ 9
= 6

Cost of 1 shirt
= 216 ÷ 6
= $36

Cost of 1 skirt
= 36 + 9
= $45

Price of 7 shirts and 10 skirts
= (7 x 36) + (10 x 45)
= 252 + 450
= $702

Answer(s): $702