Question
Mathematics Question on permutations and combinations
A five digit number divisible by 3 is to be formed by using the numerals 0, 1, 2, 3, 4 and 5 without repetition. The total number of ways in which can be done is
A
216
B
600
C
240
D
3125
Answer
216
Explanation
Solution
Since, a five-digit number is formed using the digits \\{0,1,2,3,4 and 5\\} divisible by 3 i.e. only possible when sum of the digits is multiple of three.
Case I Using digits 0,1,2,4,5
Number of ways =4×4×3×2×1=96
Case II Using digits 1,2,3,4,5
Number of ways =5×4×3×2×1=120
∴ Total numbers formed =120+96=216