8/5 ÷6 3/4 in simplify the complex fraction

If 10 men take 18 days to mow 60 acres of grass, how long will 15 men take to mow 80 acres?

Asocial networking site currently has 400,000 active members, and that figure is predicted to increase by 32% each year. the following expression represents the number of active members on the site after t years.

Acircle has a circumference of 28.36 units what is the diameter of the circle