if 4 people are selected from a group of 5 married couples , what is the probability that none of them would be married to each other ?
"if we are to select 4 people from 5 couples without any restriction , how many ways can we make the selection ? 10 ! / 4 ! 6 ! = 210 if we are to select 4 people from 5 couples with restriction that no married couple can both make it to the group , only a representative ? 5 ! / 4 ! 1 ! = 5 but we know that to select a person from each couple , take 2 possibilities 5 * 2 * 2 * 2 * 2 = 80 probability = desired / all possibilities = 80 / 210 = 8 / 21 answer : e"
multiply(multiply(multiply(divide(multiply(5, const_2), multiply(5, const_2)), divide(multiply(4, 4), subtract(multiply(5, const_2), const_1))), divide(subtract(multiply(4, 4), const_2), multiply(4, 4))), divide(subtract(subtract(multiply(4, 4), const_2), const_2), subtract(multiply(4, 4), const_1)))