In an entrance test there are multiple choice questions, there are four options for each question, of which only one is correct. The probability that a student knows the answer of a question is 90%. If he gets the correct answer to a question, then what i

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In an entrance test there are multiple choice questions, there are four options for each question, of which only one is correct. The probability that a student knows the answer of a question is 90%. If he gets the correct answer to a question, then what is probability that he was guessing? #probability question nda  #nda1 2026 probability questions

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00:00Yeah, I have a question that I have given a test,

00:03or an exam in zip.

00:05MCQ type exam.

00:07Four options of exam.

00:09And a student,

00:11he has a question of answer.

00:13He has a probability of 90%

00:15and his probability of 10%

00:19We have given a question of answer,

00:23which is right.

00:25Or he has asked,

00:26which is the probability of the answer.

00:29So, probability is equal to favorable outcome upon total outcome.

00:35Favorable outcome,

00:36yarni ki,

00:37उसने तुक्का लगाया हो.

00:38To तुक्का लगाने की probability क्या है?

00:4190% उस्ते आने के,

00:43yarni ki, 10% उस्ते नहीं आने की.

00:45To फिर बाद में,

00:4610 by total percent कितनी है?

00:49100.

00:50Yarni ki, 10 by 100 into

00:53तुक्का लगाने की,

00:54yarni ki, guess कहने की probability.

00:56Guess किया हो,

00:58और सही,

00:58by.

00:59Yarni ki,

01:004 option में से,

01:01किसी भी A के सही होने की probability,

01:031 by 4.

01:05First case A true,

01:07फिर बाद में case B true.

01:09इस इन टाइप की cases में,

01:11हम इन probability को multiply करते.

01:14A की probability multiplied by B की probability.

01:16For example,

01:18कि A B होकर हो,

01:19और B B,

01:20ऐसे cases में probability multiply होते है,

01:23centrally.

01:25अब इससे divided by,

01:27इससे simplify करेंगे,

01:29तो यह 10 upon 100 बन जाएगा,

01:301 upon 10 into 1 upon 4.

01:32टोटल आउटकम,

01:34तो answer इसने यह तो बताई रिया है कि correct है,

01:37तो फिर बाद में correct होने की probability है,

01:40पहला कि उससे अंसर आजा था,

01:429 by 10 plus,

01:44दूर्जा उसने तुक्का लगाया,

01:46फिर बाद में correct हो गया,

01:48तो फिर बाद में यह हो गया,

01:49टोटल आउटकम जितमे answer correct है,

01:52तो फिर बाद में probability आ जाएगी,

01:541 upon 40 divided by इससे एड़ किया हो,

01:589 upon 10 plus 1 upon 40,

02:02LCM लेके solve करेंगे,

02:041 upon 40 divided by 9,

02:084,36 plus 1,

02:0937 upon 40,

02:12इससे यह cancel हो गया,

02:13यानि कि यह आगे,

02:141 upon 37 probability हमारा answer,

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