Aptitude - Probability - Discussion

Please, from where E={(1,1),(1,2)...} is came? Please explain.

I am sure the answer is 1/6 for this as this event mentioned has something missing.

E = { (1, 1), (1, 2), (1, 4), (1, 6), (2, 1), (2, 3), (2, 5), (3, 2), (3, 4), (4, 1), (4, 3),
(5, 2), (5, 6), (6, 1), (6, 5) }

E(correct) = { (1,1), (1, 1), (1, 2), (1, 4), (1, 6), (2, 1), (2, 3), (2, 5), (3, 2), (3, 4), (4, 1), (4, 3), (5, 2), (5, 6), (6, 1), (6, 5) }
(1,1) will have a probability 2/12 rather than 1/12 un-like other pairs.

If you note (2,1) occurs and (1,2) also occurs and hence (1,1) due to dice A and additionally (1,1) due to dice B and hence the probability of this event is doubled.

If two numbers are selected at random, one after the other with replacement from the set A = (5, 6, 7, 8, 9). Find the probability of selecting at least one prime number.

Can anyone help me to solve this problem.

1+1=2 here 2 is not a prime number then please explain why (1, 1) used here?

Explain, please.

In the answer, why didn't they count (1,1) twice as it is possible that the number 1 might come on either of the dices, as they calculated (1,2) & (2,1)

Hi when would be the sample space be 12 and when would it be 36? I mean if a dice is thrown twice or if two dice are thrown. What would be the difference in the sample space?

Anyone tell me, why not taking (6, 3)?

Are 4 and 6 prime numbers?

4 and 6 divisible by not only 1 and itself, but it is also divisible by 2, 3.

@All.

Why here we perform addition operation to get a Prime number? Instead of getting total as prime we use (product or subtract).

Why only addition is performed? Can anybody explain this clearly!

@Sowmya.

Yes, the total score here means the sum of numbers.