Question

The probability of selecting a blue marble at random from a jar that contains only blue, black and green marbels is 1/5. The probability of selecting a black marble at random from the same jar is 1/4. IF the jar contains 11 green marbels, find the total number of marbels in the jar.

Answer 1

its answer is 20 marbles

Answer 2

Answer:let the no. Of blue marble =x..(1)

And the no. Of black marble =y...(2)

So,the total no. Of marble is = x+y+11...(3)

Then acc. To queition ,

Probability of getting a blue marble = 1/5 (given)

No.of blue marble /total no.of marble =1/5

x/x+11+y = 1/5 ...(from(1)and(3))

5x =x+11+y

5x - x - 11 - y = 0

4x - 11 - y = 0....(4)

Now,

Probability of getting a black marble = 1/4 ..(given)

No. Of black marble / total marble = 1/4

Y/x+11+y = 1/4

4y = x+ 11 +y

x +11 +y - 4y = 0

X +11 - 3y = 0....(5)

Noe solve equatin (4) and(5) by elemination you will get the value of x and y

Put the value of x and y in equation (3) you will get answer

Step-by-step explanation: