Hilda paid a total of $216 for a skirt, a pair of socks and a pair of ballet shoes. She spent ⁵₆ of her money on the pair of socks. The pair of ballet shoes cost 3 times as much as the skirt. How much more did she pay for the pair of ballet shoes than the skirt?
Amount that Hilda paid for the pair of socks
= ⁵₆ x 216 
= $180

Amount that Hilda left after buying the socks
= 216 - 180
= $36

Amount that Hilda paid for the skirt = 1 u
Amount that Hilda paid for the ballet shoes = 3 u

Total amount spent on the skirt and the pair of ballet shoes
= 1 u + 3 u
= 4 u

4 u = 36

1 u = 36 ÷ 4 = 9

Amount that Hilda paid more for the pair of ballet shoes than the skirt
= 3 u - 1 u
= 2 u
= 2 x 9
= $18

Answer(s): $18