1. 15mph = 1 mile every 4 minutes, so to travel 14 miles would be 14 x 4 or 56 minutes
2. Find a number that 21 and 35 are both divisible by - in this case 7. 3 x 7 = 21 and 5 x 7 = 35. So to travel 21 miles at 35mph would take 3/5th of an hour so 36 minutes