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```1)A carry bag contains 5 white, 8 violet and 3 pink ribbons. Four ribbons are drawn at random. What is the probability that none of the ribbons drawn is pink?

A. 10/20

B. 11/20

C. 2/7

D. 5/7

**Answer:**B. 11/20

**Explanation:**
Total number of ribbons = (5 + 8 + 3) = 16

Let S be the sample.

Then, n(S)= Number of ways of drawing 4 ribbons out of 16

= ^{16}C_{4}`

=(16 x 15)/(4 x 3)

= 20.

Let E = Event of drawing 4 ribbons, none of which is pink.

n(E) = Number of ways of drawing 4 balls out of (12) ribbons.

= ^{12}C_{4}

= (12 x 11)/(4 x 3)

= 11.

P(E) = n(E)/n(S)

=11/20

```
```2) What is the probability of getting a sum 9 from two throws of a dice?

A. 1/5

B. 1/8

C. 1/7

D. 1/9

**Answer:**D. 1/9

**Explanation:**
In two throws of a dice, n(S) = (6 x 6) = 36.

Let E = event of getting a sum

={(3, 6), (4, 5), (5, 4), (6, 3)}.

P(E) = n(E)/n(S)

=4/36

=1/9

```
```3) In a box, there are 4 green, 3 brown and 7 red balls. One ball is picked up randomly. What is the probability that it is neither green nor red?

A. 3/14

B. 3/4

C. 7/19

D. 8/21

**Answer:**A. 3/14

**Explanation:**
Total number of balls = (4 + 3 + 7) = 14.

Let E = event that the ball drawn is neither red nor green

= event that the ball drawn is brown.

n(E) = 3.

P(E) = n(E)/n(S)

=3/14

```
```4) What is the probability that a number selected from numbers 1,2,3,...,25, is prime number, when each of the given numbers is equally likely to be selected?

A. 9/30

B. 8/30

C. 9/30

D. 11/30

**Answer:** C. 9/30

**Explanation:**
Total prime no= {2,3,5,7,11,13,17,19,23}

n(E)= 9

n(S)=30

Hence required probability,

P(E) = n(E)/n(S)

=9/30

```
```5)A bag contains 20 toys numbered 1 to 20. A toy is drawn and then another toy is drawn without replacement.
Find the probability that both toys will show even numbers.

A. 5/21

B. 9/38

C. 11/42

D. 4/21

**Answer:**B. 9/38

**Explanation:**
The probability that first toy shows the even number,

= 10/20

Since, the toy is not replaced there are now 9 even numbered toys and total 19 toys left.

Hence, probability that second toy shows the even number,

= 9/19

Required probability,

P(E) = 10/20 × 9/19

=9/38

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