a fair coin is tossed 3 times . what is the probability of getting at least 2 tails ?
"let ' s find the probability of 2 tails , 3 tails p ( ttt ) = ( ( 1 / 2 ) ^ 3 = 1 / 8 . p ( htt ) = ( 3 ! / 2 ! ) * ( 1 / 2 ) ^ 3 = 3 / 8 total probablity = 1 / 8 + 3 / 8 = 1 / 2 answer ( c )"
divide(add(add(add(choose(3, const_2), choose(3, const_3)), choose(3, const_4)), choose(3, 3)), power(const_2, 3))