ANSWER :
1/8
EXPLANATION :
From the problem, there are 8 married couples in a tennis club.
There are 8 men and 8 women.
The total number of outcomes is the product between the number of first picks and the number of second picks.
For the first pick, we need to pick a man and there are 8 choices.
For the second pick, we need to pick a woman and there are 8 choices.
So the total outcome will be 8 x 8 = 64
Now, getting the probability of picking 1 man and 1 woman that are married to each other.
For the first pick, we have 8 choices for men, so we have 8.
For the second pick, we only have 1 choice over 8 women, since the woman must be married to the man, so we have 1.
That will be 8 x 1 = 8
The probability is the quotient between the required picking divided by the total number of outcome.
That will be :
8/64 = 1/8
The answer is 1/8