Question 759848
speed S is inversely proportional to the time t
     S = k/t
Where k is constant of proportionality.
To find k use given information:
     S = k/t
     10 = k/0.75
      k = 0.75 * 10
      k = 7.5
Your formula:
     S = 7.5/t
using formula:-
     S = 7.5/t
     S = 7.5/0.5
     S = 15 mph
Hope this helps.
:-)