A windmill at a wind energy factory spun 4:2 times in its first fifteen seconds of
operation and 5 times in the next fifteen seconds. The total number of times that the windmill spun during those thirty seconds is in which of the following ranges?

A At least 9 1/2and less than 10
B At least 9 1/2and less than 10)
c At least 9 2/3 and less than 103
D At least 10 2/3and less than 10%
E At least 10 5/6and less than 11 1/2