A certain pilot flew 400 miles to City K at an average speed of 350 miles per hour with the wind and made the trip back at an average speed of 450 miles per hour against the wind. Which of the following is closest to the pilot’s average speed, in miles per hour, for the round-trip? Choose the correct choice from the following choices
A) 390	B) 290	C) 300	D) 310	E) 320
390vg speed = total distance/ total time   total distance = 800   total time = 400/350 + 400/450 = 128/63   =&gt; avg speed = (800*63)/128 = 390(approx)   ans is 390
<result>A</result>
A certain pilot flew 400 miles to City K at an average speed of 350 miles per hour with the wind and made the trip back at an average speed of 450 miles per hour against the wind. Which of the following is closest to the pilot’s average speed, in miles per hour, for the round-trip?