An engineering student answered 81 questions correctly on a 90-question test. what percent of the questions did she answer correctly?

Geometry paper. i don't know how to do the rest. questions 5. 8. 9. and 10.

A50% increase followed by 33 1/2% decrease

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?