Write the ratio 2/3/4/5 in simplest form

Cassie is traveling 675 miles today to visit her brother and his family. so far, she has stopped for gas three times. at the first stop, she put in 7.1 gallons of gas and paid $23.79. at her second stop, she put in 5.8 gallons of gas and paid $19.08. and, at the third stop, 6.6 gallons and paid $20.39. at which stop did casey pay the most for gas?

Find the greatest common factor of the followig monomials 21u^5v,3u^4v^6, and 3u^2v^5

What is the sum of these mixed numbers 4 2/3+ 3 1/9