AI Mentor

Check Your IQ

Free Expert Demo

Try Test

Courses

Dropper NEET Course Dropper JEE Course Class - 12 NEET Course Class - 12 JEE Course Class - 11 NEET Course Class - 11 JEE Course Class - 10 Foundation NEET Course Class - 10 Foundation JEE Course Class - 10 CBSE Course Class - 9 Foundation NEET Course Class - 9 Foundation JEE Course Class -9 CBSE Course Class - 8 CBSE Course Class - 7 CBSE Course Class - 6 CBSE Course

Offline Centres

A bag contains white, black, and red balls only. A ball is drawn at random from the bag. The probability of getting a white ball is $310$ and that of a black ball is $25$ . Find the probability of getting a red ball. If the bag contains 20 black balls, then find the total number of balls in the bag.

see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.

An Intiative by Sri Chaitanya

Probability =

410

, Total balls = 11

Probability =

110

, Total balls = 40

Probability =

210

, Total balls = 45

Probability =

310

, Total balls = 50

answer is D.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

It is given that a bag contains white, black, and red balls only.
The probability of white ball is

310 .

The probability of black ball is

25

.
We know that, the sum of the different probability in a particular observation is always equal to 1.

P (B) + P (W) + P (R) = 1 ⇒ P (R) + 310 + 25 = 1 ⇒ P (R) = 1 − 310 − 25 ⇒ P (R) = 310

Hence, the probability of getting a red ball is

310 .

Number of black balls in the bag = 20.
Probability of getting black ball,

P (B) = n (B) n (T)

.
Where n(B)(Number of black balls) = 20 and n(T) = total number of balls.
Thus,

n (T) = n (B) P (B)

⇒ n (T) = 2025 ⇒ n (T) = 2052 ⇒ n T = 50

Hence, the probability of getting red balls is

310

and the total balls in the bag is 50.
Therefore, the correct answer is option (4).

Watch 3-min video & get full concept clarity

courses

No courses found

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

Ready to Test Your Skills?

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

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!

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 study material, now at your finger tips!

live classes
progress tracking
24x7 mentored guidance
study plan analysis

download the app

A bag contains white, black, and red balls only. A ball is drawn at random from the bag. The probability of getting a white ball is 3 10 and that of a black ball is 2 5 . Find the probability of getting a red ball. If the bag contains 20 black balls, then find the total number of balls in the bag.

Best Courses for You

Detailed Solution

courses

Get Expert Academic Guidance – Connect with a Counselor Today!

best study material, now at your finger tips!

download the app

Download the App