Probability of no couples
= 1 - Probability of 1 couple
(There cannot be more than one couple since 2 couples would mean 4 people, whereas we need only 3 people)
To have one couple, we need to select one of the 5 couples (and both people in that couple) and one person from the remaining 8 people
= 5c1 x 8c1 = 40 ways
Total number of ways to select = 10c3 = 120
Probability of having 1 couple = 40/120 = 1/3
Thus, required probability
= 1 - 1/3 =2/3
[size=80] Posted from my mobiledevice
...
= 1 - Probability of 1 couple
(There cannot be more than one couple since 2 couples would mean 4 people, whereas we need only 3 people)
To have one couple, we need to select one of the 5 couples (and both people in that couple) and one person from the remaining 8 people
= 5c1 x 8c1 = 40 ways
Total number of ways to select = 10c3 = 120
Probability of having 1 couple = 40/120 = 1/3
Thus, required probability
= 1 - 1/3 =2/3
[size=80] Posted from my mobiledevice
...
