if 4 people are selected from a group of 10 married couples , what is the probability that none of them would be married to each other ?
"if we are to select 4 people from 10 couples without any restriction , how many ways can we make the selection ? 20 ! / 4 ! 16 ! = 4845 if we are to select 4 people from 10 couples with restriction that no married couple can both make it to the group , only a representative ? 10 ! / 4 ! 6 ! = 210 but we know that to select a person from each couple , take 2 possibilities 210 * 2 * 2 * 2 * 2 = 3360 probability = desired / all possibilities = 3360 / 4845 = 43 / 62 answer : d"
multiply(multiply(multiply(divide(multiply(10, const_2), multiply(10, const_2)), divide(multiply(4, 4), subtract(multiply(10, 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)))