mathematics

posted by .

a box contains 2 white and 3 blue balls.two balls are picked at random,one after the other without replacement.what is the probof picking two balls of different colours?

  • mathematics -

    There are two cases: WB and BW

    P(WB)=(2/5)*(3/4)=3/10
    P(BW)=(3/5)*(2/4)=3/10
    Probability of choosing balls of different colours = 6/10=3/5.

    Check:
    For same colours
    P(WW)=(2/5)*(1/4)=1/10
    P(BB)=(3/5)*(2/5)=3/1

    P(all)=10/10 OK.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. math

    Four balls are selected at random without replacement from an urn containing three white balls and five blue balls. Find the probability that two or three of the balls are white. (Round your answer to three decimal places.)
  2. math

    A box contains 8 blue balls and 2 red balls. Three balls are selected from the box at random without replacement. Find the probability that two balls are blue and one ball is red.
  3. Basic Mathematics

    A bag contains 2 red balls, 3 blue balls and 5 green balls. 3 balls are drawn at random. Find the probability that a) the 3 balls are of different colours b) 2 balls are of the same colour c) all the 3 are of the same colour.
  4. Finite

    A box contains 8 blue balls, 3 white balls, and 5 red balls, and that we choose two balls at random from the box. What is the probability of neither being blue given that neither is white?
  5. statistics

    A jar contains 7 red balls, 5 green balls, 4 blue balls, and 3 white balls. A sample of size 7 balls is selected at random without replacement . Find t the probability that sample contains two red balls, 2 green balls, 2 blue balls, …
  6. stats

    A box contains 10 red balls and 20 blue balls. Three balls are selected at random one after the other from the box, without replacement. If the first two balls selected are both blue, what is the probability that the third ball selected …
  7. statistics /pure maths

    A box contains N identical balls of which 4 are Red, 3 are Green and the rest are White . If 3 balls are drawn at random one after the other without replacement.the probability that all 3 balls are Whit is 1/22. 1.Find the number of …
  8. GEOMETRY

    if two balls are drawn without replacement from a box containing 4 blue balls, 3 yellow balls, and 2 white balls, what is the probability of getting 2 yellow balls?
  9. Math

    A box contains some red balls and some blue balls. There are four more blue balls than red balls. A ball is removed at random, replaced and a second ball randomly removed. The probability that the two balls are different colours is …
  10. Math

    A box contains some white balls and some blue balls. There are 5 more blue balls than white balls. One ball is removed at random and not replaced. A second ball is then removed at random. The probability that the balls are different …

More Similar Questions