SOLUTION TO LAST MONTH'S QUIZ
1. 3/20
2. 3/11
3. 7/38
Notes.
1. 3 equiprobable houses out of 20.
2. 9 equiprobable children out of 33.
3. No. of possible pairs = 20 * 19 / 2 = 190
No. of pairs, both with 0 children = 6
No. of pairs, both with 1 child = 15
No. of pairs, both with 2 children = 10
No. of pairs, both with 3 children = 3
No. of pairs, both with 4 children = 1
Total = 35
So probability = 35/190.
