Hello Lesarinn

Welcome to Math Help Forum!There are two different cases to consider:

- (i) The ball taken from bowl A is red; and then the ball taken from bowl B is red.

- (ii) The ball taken from bowl A is not red; and then the ball taken from bowl B is red.

Work out the probabilities and that the ball taken from A is (i) red, and (ii) not red. Then, by considering the number of red balls in bowl B in each case (i) and (ii), work out the probabilities and that the second ball is red.

Finally, multiply by ; multiply by ; then add your answers to get the final answer. I reckon this comes out as .

Work out all the ways in which the total could be 5; then work out the probability that each of these sequences of numbers occurs. Finally add all your answers together to get the overall probability.Problem 2:

Given are:

S1 = {1,2,3,4}

S2 = {1,2,3,4,5,6}

S3 = {1,2,3,4,5,6,7,8}

We pick one number randomly from S1, where there is an equal chance of picking any one number. We do the same with S2 and S3.

What are the odds that the sum of the numbers we picked are equal to 5?

Thanks in advance for all your help.

I'll start you off. We could have:

- 1,1,3. The probability of this is .

- 1,2,2. The probability of this is exactly the same:

- ... and so on.

I reckon that the answer is .

Can you complete these now?

Grandad