a searchlight on top of the watch - tower makes 6 revolutions per minute . what is the probability that a man appearing near the tower will stay in the dark for at least 10 seconds ?
"6 revolutions per minute = 1 revolution every 10 seconds so no matter what anybody appearing at the tower can not stay in the dark for more than 10 seconds . this will be our total number of possibilities i . e the denominator . p ( man in dark for at least 10 seconds ) = 1 - p ( man in dark for max of 10 seconds ) = 1 - 10 / 10 = 1 - 1 = 0 or the other way would be : p ( man in dark for at least 10 seconds ) is like saying he can be in dark for 5 , 6,7 . . . all the way to 10 seconds because that is the max . in this approach it would be 10 / 10 seconds = 1 . answer is e"
subtract(const_1, divide(10, divide(multiply(const_60, const_1), 6)))