Question

A box contains 25 notes, Rs 1 is marked on 19 notes of them and Rs 5 on remaining notes. Another box B contains 50 notes in it Rs 1 is marked on 45 notes of them and Rs 13 is marked on the remaining notes. All the noted of two given boxes are collected and put them into another box and mixed them properly.A note is at random drawn from this box. What is the probability that the note drawn has some thing else beside Rs 1. 

Answer 1

Total number of notes in the boxes A and B 

= 25 + 50 = 75.

∴ Total number of all possible outcomes = 75

The number of notes on which Rs 1 is marked 

= 19 + 45 = 64

Number of notes on which Rs 1 is not marked 

= 75 – 64 = 11

Let the event that the note contains some thing else but Rs 1 be (A).

∴ The number of favourable outcomes of event (A)

= 11.

⇒ P(A) = \(\frac { 11 }{ 75 }\)

Hence P(A) = \(\frac { 11 }{ 75 }\)