29,554 views
25 votes
25 votes
Can sumone help me wit this

Can sumone help me wit this-example-1
User Pmishev
by
2.6k points

2 Answers

10 votes
10 votes

Answer:

1/9

Explanation:

Well the chance of picking 3 one time is 1/3

The chance of picking 3 the second time is 1/3

So at first, we've succeeded with probability 1/3 and failed with probability 2/3

We don't care what happens next if we've failed - we already failed.

So we've reached the "picking the second card with hope in our hearts" 1/3 of the time and we again succeed with 1/3 of a chance, so the total probability of success is 1/3 * 1/3 = 1/9

Think of the options:

3 and 3 - probability 1/3 * 1/3 = 1/9

3 and non-3 - probability 1/3 * 2/3 = 2/9

non-3 and 3 - probability 2/3 * 1/3 = 2/9

non-3 and non-3 - probability 2/3 * 2/3 = 4/9

Note that all the options sum to 1 - as probabilities of all options always should.

User Benjamin RD
by
2.8k points
22 votes
22 votes

Answer:

1/9 i think not sure

Explanation:

User Split
by
3.2k points