Can someone please help me with 13-16 it’s urgent guys no one is helping me

Christina can paint 420 square feet in 105 minutes. which unit rate describes the scenario?

Dean and karlene get paid to write songs. dean is paid a one-time fee of $20 plus $80 per day. karlene is paid a one-time fee of $25 plus $100 per day. write an expression to represent how much a producer will pay to hire both to work the same number of days on a song.

Which number produces an irrational number multiplied by 1/3