How many feet per second do you fall when parchuting

With an open parachute, it takes about 24 and a half minutes to descend from 40,000 feet. The landing speed is about 14 miles an hour.  

Ithink the answer is d. not sure but don’t answer it.

1. 0.3 •4 is the same as 4 groups of 0.32. 7•0.8 is the same as 7 groups of 0.83. it increases by 0.5 every time, so 0.5x4 it increases by 0.9 every time, so 0.9x5. 0.9•12=10.86. 0.47•5=2.35i can finish the next ones in a separate post