Question

1. In a pen holder, there are some pens. Out of the total pens, 8 are red, 7 are blue, and the rest
are green. If the probability of getting a red pen is 2, then find the total number of pens in
the pen
holder and the probability of getting a green pen.
A die is rolled 8 times. What is th
5​

Answer 1

Answer, (1)

(a)let x be the green pens, so the total pens are =8+7+x=15+x

Red pens are =8 , A probability can not be more than 1 so i am guessing it is (1/2) not 2, Alright

P(red)=1/2=N(red)/N(total)=(8)/(15+x)

15+x=16

x=16-15=1

So the total number of pens are =7+8+1=16

(b)

Probability of Getting a green pen is P(green)=N(green)/N(Total)=1/16

Next question is incomplete

Answer 2

Given:– no. of red pens = 8

no. of blue pens = 7

let the total no of pen be x.

Then, no. of green pen = x- ( 8+7) = x-15

A/q

P(red pen) = 1/2 = 8/x

On comparing LHS & RHS,

x = 16

Total no. of pens = 16

So, no. of green pen = 16-15 = 1

P(green pen) = 1/16