we have 1 hour = 2 miles
so miles 1/3 2/3 1 2 4
time 1/6 1/3 1/2 1 2
see with time the first three times it went up by 1/6: 1/6 + 1/6 = 2/6 or 1/3 so if each 1/6 = 1/3 than 1/3 + 1/3 = 2/3
than 1/6 + 1/6 + 1/6 = 3/6 or 1/2 so 1/3 + 1/3 + 1/3 = 3/3 or 1 mile or take 2 x 1/2 = 1
you were given 1 hour = 2 mile, than for the 2 hour mark just take 2 hours times 2 miles (2 x 2 = 4)