Banner 0
Banner 1
Banner 2
Banner 3
Banner 4
Banner 5
Banner 6
Book Online Demo
Check Your IQ
Try Test

Courses

Dropper NEET CourseDropper JEE CourseClass - 12 NEET CourseClass - 12 JEE CourseClass - 11 NEET CourseClass - 11 JEE CourseClass - 10 Foundation NEET CourseClass - 10 Foundation JEE CourseClass - 10 CBSE CourseClass - 9 Foundation NEET CourseClass - 9 Foundation JEE CourseClass -9 CBSE CourseClass - 8 CBSE CourseClass - 7 CBSE CourseClass - 6 CBSE Course
Offline Centres

Q.

A bag contains 12 balls out of which x are white. If 6 more white balls are put in the bag, the probability of drawing a white ball will be double than that in first case. Find x.


see full answer

Talk to JEE/NEET 2025 Toppers - Learn What Actually Works!

Real Strategies. Real People. Real Success Stories - Just 1 call away
An Intiative by Sri Chaitanya

a

7

b

4

c

3

d

2 

answer is C.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

Given that, if 6 more white balls are put in the bag, the probability of drawing a white ball will be double than that in first case.
The number of balls is 12 out of which x   is white.
For an event E, probability is given by,
P E = Number of favourable outcomes n(E) Total number of outcomes n(S)  
Therefore, the probability that the randomly drawn ball is a white ball is,
P E = x 12  
Now, the number of white balls is x+6 and the total number of balls is 12+6=18
So,
The probability that the randomly drawn ball is white after 6 white balls are added is,
P 1 E = x+6 18  
According to the given condition,
P 1 E =2×P E  
⇒ x+6 18 =2× x 12 ⇒ x+6 18 = x 6 ⇒6x+36=18x ⇒36=12x ⇒x=3  
So, the value of x is 3.
Therefore, option 3 is correct.
 
Watch 3-min video & get full concept clarity
Related Blogs
Get ₹ 1 crore* worth scholarship for JEE / NEET / Foundation
Result Producing online coaching for JEE/NEET of south India
Largest All India Test Series for JEE/NEET
Best Online Course for IIT JEE
Best Online Course for NEET
Best Online Course for CBSE

Best Courses for You

JEE

JEE

NEET

NEET

Foundation JEE

Foundation JEE

Foundation NEET

Foundation NEET

CBSE

CBSE

score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

Related Blogs
Get ₹ 1 crore* worth scholarship for JEE / NEET / Foundation
Result Producing online coaching for JEE/NEET of south India
Largest All India Test Series for JEE/NEET
Best Online Course for IIT JEE
Best Online Course for NEET
Best Online Course for CBSE
whats app icon
A bag contains 12 balls out of which x are white. If 6 more white balls are put in the bag, the probability of drawing a white ball will be double than that in first case. Find x.