Explanation:
The fraction 5/2 turns into 10/4 when you multiply top and bottom by 2
5*2 = 10
2*2 = 4
Or you could use long division or a calculator to notice that
5/2 = 2.5
10/4 = 2.5
Both result in the same exact decimal value, so the fractions must be equal. Each person runs exactly 2.5 miles everyday.