## pooja123 2 years ago a bag contains 3white and 4red balls.two draws of one ball each are made without replacement.what is the probability that one is red and other is white

Probability one is red of the first draw is 4/7 Probability one is white of the 2nd draw is 3/6 =1/2 multiply of both up, we get 4/7 * 1/2 = 4/14 = 2/7

does that make sense, @pooja123 ?

3. pooja123

4/7 is just for the probalility of one red only :) do u want draw 2 balls, right ?

5. pooja123

yes they used the formula like 2into4into3/7into 6

hmm. i dont understand that, actually the formula to get the probability of an event using : P(A) = number of event A / number all event

7. nubeer

hmm well she is right the answer would be 4/7

why, can u explain more, nubber ?

9. nubeer

we found the probability 2/7 when first red and second white so P[RW] = 2/7 this is one case another possibility is that first is white and second is red P[WR] = 3/7 * 4/6 = 2/7 so total probability of this event = p[WR]+p[RW]

10. pooja123

thanks

wait, is draw it one by one Or 2 balls direct ?

12. nubeer

hmm i think one by one...

hmmmm.. yeah, i see now. the question doesnt says the the first draw must red or white, thanks for your corrections @nubeer and sorry for @pooja123 :)

14. nubeer

15. pooja123

thank u guys

im not becareful with this question :)

17. pooja123

k

18. 1411akshay

can u see my isosceles triangle solution for one sec