Explain why it is necessary to rename 4 1/4 if you subtract 3/4 from it

Combined megan and kelly worked 60 hours. kelly worked twice as many hours as megan. how many hours did they each worked?

Answer this 30 points and brainliest!

Problem melissa is her dad build a walkway in their backyard. the walkway will be 54 feet long and 1.5 feet wide. the local hardware store sells tiles which are 1.5 by 1.5 feet and come in boxes of 12. how many boxes of tiles do they need?