A plane flies 420 miles with the wind and 350 miles against the wind in the same length of time. If the speed of the wind is 15 ​mph, find the speed of the plane in still air.

Two friends are reading books. jimmy reads a book with 21,356 words. his friend bob reads a book with one-and-a-half times as many words. which expression represents the number of words bob reads?

Siri can type 90 words in 40 minutes about how many words would you expect her to type in 10 minutes at this rate

Can someone show me step by step how to do this?