Question

30. Ten percent of the black balls were added to
twenty percent of the white balls and the balls
were 24. Three times the number of black
balls exceeds the number of white balls by 20.
Find the number of black balls and also, the
number of white balls.​

Answer 1

Answer:

No of black balls=40

No of white balls=100

Step-by-step explanation:

First, we assume that no of black balls =x

No of white balls=y

Then acc to ques

Two equation are formed as shown in image

The equations are

X+2y=240

3x-y=20

Then by solving them we get the no of balls x=40 and y=100

THANK YOU

Answer 2

Answer

________

Black 40. White 100

Step-by-step explanation:

A bag contains 20 balls out of which x are black. If 10 more black balls are put in the box, the probability of drawing a black ball is double of what if was before. The value of x is:

Medium

Solution

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Correct option is B)

Probability of black balls =

20

x

Probability of black balls after adding 10 new balls =

30

x+10

According to the question

=

30

x+10

=

20

2x

20x+200=60x

⇒40x=200⇒x=5