A jet flies 852 miles with a tailwind in half the time it takes to fly 1560 miles against the same wind. Find the jet’s speed, if the wind speed is 18mph.
Let s = speed of the jet and t = time it takes to fly 852 miles. So (s+18)*t = 852 and (t-18)*2t = 1560. Divide 2 from the second equation, we have (t-18)*t = 780. Now divide the first equation by the new second equation, we have (s+18)/(s-18) = 852/780. Cross multiply we have 852(s-18) = 780(s+18). Solving for s, we have s = 408 mph.