# NCERT Class 11-Math՚S: Exemplar Chapter – 16 Probability Part 7 (For CBSE, ICSE, IAS, NET, NRA 2022)

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**Question 6**:

In a large metropolitan area, the probabilities are . that a family (randomly chosen for a sample survey) owns a colour television set, a black and white television set, or both kinds of sets. What is the probability that a family owns either anyone or both kinds of sets?

**Answer**:

**Question 7**:

If A and B are mutually exclusive events, and , find

(a)

(b)

(c)

(d)

(e)

(f)

**Answer**:

(a)

(b)

(c)

(d)

(e)

(f)

**Question 8**:

A team of medical students doing their internship have to assist during surgeries at a city hospital. The probabilities of surgeries rated as very complex, complex, routine, simple or very simple are respectively, . Find the probabilities that a particular surgery will be rated

(a) Complex or very complex;

(b) Neither very complex nor very simple;

(c) Routine or complex

(d) Routine or simple

**Answer**:

(a)

(b)

(c)

(d)

**Question 9**:

Four candidates A, B, C, D have applied for the assignment to coach a school cricket team. If A is twice as likely to be selected as B, and B and C are given about the same chance of being selected, while C is twice as likely to be selected as D, what are the probabilities that

(a) C will be selected?

(b) A will not be selected?

**Answer**:

(a)

(b)

**Question 10**:

One of the four persons John, Rita, Aslam or Gurpreet will be promoted next month. Consequently the sample space consists of four elementary outcomes S = {John promoted, Rita promoted, Aslam promoted, Gurpreet promoted} You are told that the chances of John՚s promotion is same as that of Gurpreet, Rita՚s chances of promotion are twice as likely as Johns. Aslam՚s chances are four times that of John.

(a) Determine P (John promoted)

P (Rita promoted)

P (Aslam promoted)

P (Gurpreet promoted)

(b) If .

**Answer**:

(a)

(b)