Question
Question: Total number of four digit odd numbers that can be formed using 0, 1, 2, 3, 5, 7 are....
Total number of four digit odd numbers that can be formed using 0, 1, 2, 3, 5, 7 are.
A
216
B
375
C
400
D
720
Answer
720
Explanation
Solution
0, 1, 2, 3, 5, 7 : Six digits
The last place can be filled in by 1, 3, 5, 7. i.e., 4 ways as the number is to be odd. We have to fill in the remaining 3 places of the 4 digit number i.e. I, II, III place. Since repetition is allowed each place can be filled in 6 ways. Hence the 3 place can be filled in 6 × 6 × 6 = 216 ways.
But in case of 0 = 216 – 36 = 180 ways.
Hence by fundamental theorem, the total number will be = 180 × 4 = 720.