Question

A box has 100 red balls, 50 blue balls and 50 black balls. 50% of the blue balls and 25% of the red balls were taken out of the box. Now if one ball is picked . What is the probability of picking a black ball ?

Answer 1

the correct answer is 50/250

Answer 2

Answer:

$\text{The probability is }\frac{1}{3}$

Step-by-step explanation:

Given that a box has 100 red balls, 50 blue balls and 50 black balls. 50% of the blue balls and 25% of the red balls were taken out of the box. Now if one ball is picked.

we have to find the probability of picking a black ball.

Red balls=100

Blue balls=50

Black balls=50

50% of the blue balls and 25% of the red balls were taken out of the box.

$\frac{50}{100}\times 50=25 blue\thinspace balls$

$\frac{25}{100}\times 100=25 red\thinspace balls$

Hence, 25 blue balls and 25 red balls are take out of box then box remains

Red balls=100-25=75 balls

Blue balls=50-25=25 balls

Black balls=50

Total balls=75+25+50=150 balls

$\ext{P(a black ball)=}\frac{\text{Number of black balls}}{\text{Total number of balls}}$

$=\frac{50}{150}=\frac{1}{3}$

$\text{The probability is }\frac{1}{3}$