7) At the ice rental stand, 60% of 100 skates are for boys. If the 20% of rest are for elders, how many skates are for girls?

60% of 100 = 60. Therefore, 60 skates are reserved for boys.

Remaining = 100-60= 40

20% of 40 are for elders and 20% of 40 means (20/100)*40 = 8.

8 skates are reserved for elders and 40-8=32 are reserved for girls.