240 minutes would be 4 hours. 15 miles times 6 is 90 miles. so you take 240 and times it by 6. which equals, 1440. so it would take 1440 minutes to fly 90 miles. hope this helps!
First figure out how many times 15 can go into 90. 90/15=6 So you now know that it takes him 6 times the amount of time. So you would multiply 4 and 6 4*6=24 It will take the bird 24 hours to travel 90 miles. Hope this helps.