There are only nred balls and (n + 1) blue balls in a bag, Shamsa takes at random 2 balls from the bag,
Find an expression for the probability that both balls are the same colour,

M∠abc=138° and m∠def=31° . which statement is true about ∠abc and ∠def ? a: the angles are neither complementary nor supplementary. b: the angles are complementary. c: the angles are supplementary.