How to do ratio questions

Shryia read a 481 -page-long book cover to cover in a single session, at a constant rate. after reading for 1.5 hours, she had 403 pages left to read. how fast was shryia reading? pages per hour how long did it take her to read the entire book? hours plz i realy need this

One side of a rectangle is 7 feet shorter than seven times the other side. find the length of the shorter side if we also know that the perimeter of the rectangle is 306 feet.

How many credit hours will a student have to take for the two tuition costs to be equal? round the answer to the nearest tenth of an hour.