Question
A four-digit number is formed by using the digits 1, 2, 4, 8 and 9 without repitition. If one number is selected from those numbers, then what is the probability that it will be an odd number?

Answer

  1. $\frac25$
Solution:
Total number of outcomes = 5 × 4 × 3 × 2 = 120
The number of favourable cases = 2(4 × 3 × 2) = 48 (i.e., odd numbers)
Therefore,
Required probability $\frac{48}{120}=\frac25$

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