At open skate night, admission is $3.75 with a membership card and $5.00 without a membership card. Skate rentals are $3.00.

The Moores And Cotters were at Open Slate night. The moores paid $6.00 more for skate rentals than the Cotters did. Together, the two families paid $30 for skate. How many pairs of skates did the Moores rent?

Price paid:

moores = cotters + 6

moores + cotters + 6 = 30

therefore:

moores + cotters = 24

[substitute moores = cotters + 6 into moores + cotters = 24]

cotters + 6 + cotters = 24

2 cotters = 18

cotters = 9

[substitute cotters = 9 into moores = cotters + 6]

moores = 9 + 6 = 15

you haven't said of the families have membership, but on skate rentals alone:

15 / 3 = 5 pairs of skates