Question
Question: The sum of the digits in the unit place of all numbers formed with the help of 3, 4, 5, 6 taken all ...
The sum of the digits in the unit place of all numbers formed with the help of 3, 4, 5, 6 taken all at a time is
A
18
B
108
C
432
D
144
Answer
108
Explanation
Solution
Required sum = 3! (3 + 4 + 5 + 6)
= 6 x 18 = 108