Question

a bag contains 5 pencils and some pens if the probability of drawing a pen is double that of a pencil find the number of pens in the bag.

Answer 1

$\boxed{\mathbb{\red{\huge{heya \: mate}}}}$

Let there be x no. of pens in the bag.

Therefore,

Total number of pens in the bag = (5 + x)

Now,

P1 =Probability of drawing a pens =$= \frac{x}{5 + x}$

P2 =Probability of drawing a pencil =$= \frac{5}{5 + x}$

According to the question,

P1 = 2 × P2

≈>$\frac{x}{5 + x} = 2 \: \times \frac{5}{5+ x}$

$\frac{x}{5 + x} = \frac{10}{5 + x}$

Cross multiple each other we get,

$x(5 + x) = 10(5 + x)$

$\huge \boxed{x = 10}$

Hence, there are 10 pens in the bag.

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Answer 2

Hey mate,

Double means *2

So here it Is going to be 5*2 = 10
So ans is 10 pens