Paul drove from his house to work at an average speed of 40 miles per hour. The drive took him 15 minutes. If the drive home took him 20 minutes and he used the same route in reverse, what was his average speed going home? (This deals with direct and indirect variations)

Question

anonymous · Answer

This problem can be solved using a ratio. you find the ratio between 15/20 and then multiply that by 40 and thus you arrive at the average speed going home.

anonymous · Answer

So you would get 53 (1/3)

anonymous · Answer

nope, what did you get for 15/20?

anonymous · Answer

.375

anonymous · Answer

there's your mistake, 15/20 simplifies down to 3/4 which is .75

anonymous · Answer

from there you multiply .75 by 40

anonymous · Answer

it's 40 minutes to 15 min
minutes though

anonymous · Answer

its 40 miles, not 40 minutes.

anonymous · Answer

That's what I meant

anonymous · Answer

Anyway, the proportion would be 40:15, or .375

anonymous · Answer

you can think of the equation set up as 40 * 15 = 20x, solve for x

anonymous · Answer

Thanks!

anonymous · Answer

hope i helped. sorry if i confused you.

anonymous · Answer

No, you're good.