## Book: Mathematics Part-II

### Chapter: 13. Probability

#### Subject: Maths - Class 12th

##### Q. No. 13 of Miscellaneous Exercise

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13
##### Assume that the chances of a patient having a heart attack are 40%. It is also assumed that a meditation and yoga course reduce the risk of heart attack by 30% and prescription of certain drug reduces its chances by 25%. At a time a patient can choose any one of the two options with equal probabilities. It is given that after going through one of the two options the patient selected at random suffers a heart attack. Find the probability that the patient followed a course of meditation and yoga?

Let us assume, X denotes the events having a person heart attack

A1 denote events having the selected person followed the course of yoga and meditation

And, A2 denote the events having the person adopted the drug prescription

It is given in the question that,

P (X) = 0.40

And,

Probability (The patient suffering from a heart attack and followed a course of meditation and yoga):

=

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