Question

A bag has 15 balls 10 pens and five pencils if two objects are chosen at random what is the probability that both of them are pencils

Answer 1

The total number of items in the bag is :

15 + 10 + 5 = 30

The probability of getting a :

Pencil = 5/30 = 1/6

Pen = 10/30 = 1/3

Ball = 15/30 = 1/2

The probability of getting two pencils is :

P (getting a pencil) and P (getting a pencil)

In probability this is expressed as :

P (getting a pencil) × P (getting a pencil)

1/6 × 1/6 = 1/36