Hi I’m kind of confused

You’re ordering more thread for blue jeans co. you usually purchase from ted’s threads, which sells 12 thread spools for $27. you recently received a notice from wade's wares that says you can buy thread from them for $2.30 each for the first 2 dozen and $2 a spool thereafter. you need to order 5 dozen spools. what percentage can you save by going with wade’s wares?

K-7/4=11 explanation: k-7 is the numerator and 4 is the denominator then right by it it just says = 11 ( i wish i knew how to do this but ummm i cant sis)

Arectangle has a perimeter of 20 cm. the length, x cm, of one side of this rectangle is uniformly distributed between 1 cm and 7 cm. find the probability that the length of the longer side of the rectangle is more than 6 cm long.