Question

the bag contains 3 red and 4 blue marbles is drawn at random what is probability of drawing red marbles​

Answer 1

Answer:

1/9

Step-by-step explanation:

hope it will help u friend

Answer 2

Answer:

Label the marbles b1,b2,b3,b4 and r1,r2,r3,r4,r5,r6

From the urn one can draw:

b1 and either b2,b3,b4,r1,r2,r3,r4,r5, or r6 note: 3 of 9 are black pairs

b2 and either b1,b3,b4,r1,r2,r3,r4,r5, or r6 note: 3 of 9 are black pairs

b3 and either b1,b2,b4,r1,r2,r3,r4,r5, or r6 note: 3 of 9 are black pairs

b4 and either b1,b2,b3,r1,r2,r3,r4,r5 or,r6 note: 3 of 9 are black pairs

r1 and either b1,b2,b3,b4,r2,r3,r4,r5 or,r6 note: 0 of 9 are black pairs

this is true for r2,r3,r4,r5, and r6 note: 0 of (5*9=45) are black pairs

So the probability of drawing a black pair is 12 / 90.

If you consider drawing b1 then b2 is the same as drawing b2 then b1

and drawing r3 then b4 is the same as drawing b4 then r3 and so on…

Then there are only 6 black pairs and only 45 outcomes -- 6 / 45

12 / 90 = 6 / 45 = 2 / 15

To: Peter Robertson

You are correct that there are 4/(4+6) ways to draw a black marble in the first draw and, without replacement, there are 3/(3+6) ways to draw a black marble in the second draw. In this approach, one doesn’t distinguish one black marble from another (same for red) so order doesn’t matter -- there is no reason to divide by 2.

So the answer is 4/10 x 3/9 = 12/90 = 6/45 = 2/15. Hope that this helps.

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Step-by-step explanation: