Can someone please help me? I need what e equals

If an athlete can bike 6 miles in 25 minutes, how many miles will he bike in an hour and half if he continues to bike at the same rate?

Collin did the work to see if 10 is a solution to the equation r/4=2.4

Asunflower was 20 1/2 inches tall. over the next 6 months, it grew to a height of 37 inches tall. what was the average yearly growth rate of the height of the sunflower? ? plz write a proportion to solve i will give you 100 points