Discussion Forum

A four-digit number is formed by the digits 1,2,3, 4 with no repetition. The probability that the number is odd, is 

Answer:

Explanation:

Given digits are 1,2,3,4

 Possibilities for units place digit (either 1 or 3)=2

 Possibilities for ten 's' digit=3

 Possibilities for hundred's place digit=2

 Possibilities for thousand  place's digit=1

 $\therefore$  Number of favourable outcomes

=$2 \times 3 \times2 \times 1=12$

 Number of numbers formed by 1,2,3,4(without repetitions)=4!

 $\therefore$ Required probability = $\frac{12}{4 \times 3 \times 2}=\frac{1}{2}$