Question

How many of the numbers formed are divisible by 3 ? why ?​

Answer 1

Answer:

Since a five-digit number is formed by using digits 0,1,2,3,4 and 5, divisible by 3 i.e., only possible when the sum of digits is multiple of three which gives two cases.

Case I: Using digits 0,1,2,4,5 the number of ways =4×4×3×2×1=96.

Case II: Using digits 1,2,3,4,5 the number of ways =5×4×3×2×1=120

Therefore, total number formed =120+96=216.