if x is to be chosen at random from the integers between 1 to 7 , inclusive , and y is to be chosen at random from the integers between 7 and 11 , inclusive , what is the probability that x + y will be even ?
"x + y will be even if x and y are both even or both odd . p ( x and y are both even ) = 3 / 7 * 2 / 5 = 6 / 35 p ( x and y are both odd ) = 4 / 7 * 3 / 5 = 12 / 35 p ( x + y is even ) = 6 / 35 + 12 / 35 = 18 / 35 the answer is d ."
divide(add(multiply(const_2, const_2), multiply(const_3, const_2)), multiply(7, subtract(7, 1)))