45 girls and 60 boys are present at a party . there are 17 girl - boy are in relationship among them . if a girl and a boy is selected at random , what is the probability that they will be a couple ?
"in how many ways we can select a girl and a boy from 45 lady and 60 gentlemen ? in 45 * 60 = 2,700 ways . we have a total of 17 couples so , the probability of selecting a couple is 17 / 2,700 = 17 / 2700 . ans - d"
divide(subtract(multiply(choose(45, const_1), choose(60, const_1)), choose(17, const_1)), multiply(choose(45, const_1), choose(60, const_1)))