Xandra paid a total of $140 for a cardigan, a pair of socks and a pair of high heels. She spent ⁵₇ of her money on the pair of socks. The pair of high heels cost 4 times as much as the cardigan. How much more did she pay for the pair of high heels than the cardigan?
Amount that Xandra paid for the pair of socks
= ⁵₇ x 140 
= $100

Amount that Xandra left after buying the socks
= 140 - 100
= $40

Amount that Xandra paid for the cardigan = 1 u
Amount that Xandra paid for the high heels = 4 u

Total amount spent on the cardigan and the pair of high heels
= 1 u + 4 u
= 5 u

5 u = 40

1 u = 40 ÷ 5 = 8

Amount that Xandra paid more for the pair of high heels than the cardigan
= 4 u - 1 u
= 3 u
= 3 x 8
= $24

Answer(s): $24