Answer:
$24
Step-by-step explanation:
Original price of blouse = $18
Discounted price of blouse = 3/4 x 18 = $13.50
Discounted blouse + discounted skirt = $31.50
⇒ 13.50 + discounted skirt = 31.50
⇒ discounted skirt = 31.50 - 13.50 = 18
Let S be the original price of the skirt.
If the discounted skirt is 3/4 of it's original price, then
$18 = (3/4) S
S = 18 ÷ 3/4 = 24
Therefore, the original price of the skirt is $24