when I triple a number and add 20 i will get 5he same answer as i do when i subtract the number from 40 find the number

It took alice 5 5/6 hours to drive to her grandparents' house for . on the way home, she ran into traffic and it took her 7 3/8 hours. how much longer did the return trip take? write your answer as a proper fraction or mixed number in simplest form. the trip home took __hours longer. ?

With both problems. a.s.a.p directions on photo ^

If the value of cos330°is√3/2 then find cos 165°.