In a bag containing 3 black balls and 2 red balls , a ball is picked at random then replaced. A second ball is chosen. What is the probability of :

I. both balls being black II. one is black ,the other is red.

2.in a class of 22 boys and 18 girls , two students are to be selected .
What is the probability of selecting two students of the same sex.​

3 black and 2 red balls, total number is 5

i) Both balls are black:

ii) Black and red balls:

22 boys and 18 girls, total number is 40

Combinations of 2 students:

Combination of 2 boys:

Combination of 2 girls:

Probability of selecting 2 students of the same sex:

answer: the answer is 5/22

step-by-step explanation: if you subtract 17 from 22 the answer is 5 therefore the remainder of students are female

the 3rd option is right

step-by-step explanation: