Si una yarda tienen 3 pies, ¿Cúantos pies tienen 4 yardas?

Iam so stuck. what is the worked out answer for this question?

Tamera puts 15/4 gallons of gasoline in her car. which mixed number represents the gallons of gasoline? a) 2 3/4 gallons b) 3 1/4 gallons c) 3 3/4 gallons d) 4 1/2 gallons answer it's worth a lot of points!

The ratio of men to women working for a company is 4 to 5 . if there are 90 women working for the company, what is the total number of employees?