David can type 90 words a minute. How many words can be typed in 9.5 minutes?

Can someone me and do the problem plz so i can understand it more better

What power can you write to represent the volume of the cube shown? write the power as an expression with a base and an exponent and then find the volume of the cube

Suppose you are an avid reader and are looking to save money on the cost of books instead of paying about $20 for each book, you decide to look into purchasing a kindle for $120 you can purchase e-books for about $5 each 1. find the slope-intercept equation for the cost of the hard copy of books using x to represent the number of books 2. find the slope-intercept equation for the cost of the kindle with cost of e-books using x to represent the number of books