Her rate is five miles an hour. it is 1/2 a mile in 1/10 of an hour. you need to find 10/10 of an hour, so you multiply by 10. 1/2 x 10/1. 1 x 10 is 10. 2 x 1 is 2. so the answer would be 10/2, but it can be simplified. 10 and 2 have 2 in common. 10 divided by 2 is 5 and 2 divided by 2 is one. therefore the answer is 5/1, or just five. so 5 miles per hour. (or you can just do half of ten is five ;) )
