The President of a company traveled 1600 miles by jet and 40

The President of a company traveled 1600 miles by jet and 400 miles on a prop plane. The rate of the jet is four times the rate of the prop plane. The entire trip took 10 hours. Find the rate of the jet plane. ___mph
I tried 1600/4x+ 400/x = 10 hours and my answers was 160 mph which apparently is wrong How would I set this up to get the correct answer. I am an online student and this answer is due by 10 p.m. 2-11-2010

Solution

x is the prop rate

your equation is fine

multiplying by 4x ___ 1600 + 4(400) = 10(4x)

3200 = 40x ___ x = 80

4x (jet rate) = 320