if an integer n is to be chosen at random from the integers 1 to 84 , inclusive , what is the probability that n ( n + 1 ) ( n + 2 ) will be divisible by 8 ?
"n ( n + 1 ) ( n + 2 ) will be divisible by 8 when n is a multiple of 2 or when ( n + 1 ) is a multiple of 8 . thus when n is even , this whole expression will be divisible by 8 . from 1 to 84 , there are 42 even integers . now when ( n + 1 ) is multiple by 8 , we have 12 such values for ( n + 1 ) probability that n ( n + 1 ) ( n + 2 ) will be divisible by 8 = ( 42 + 12 ) / 84 = 54 / 84 = 9 / 14 ans is a"
divide(add(divide(84, 2), divide(84, 8)), 84)