3/4•3/4 I can’t do it in my head and I don’t know how to make a decimal into a fraction

Olivia uses the work below to determine 55% of 720 which explains the error in olivia’s solution

"you know, playing tennis is healthier than watching a tennis match on television," katya remarked to her couch potato brother. in this sentence, healthier is a/an a. superlative. b. comparative. c. positive form. d. adverb.

What is best way to getting answer for my exam is