Question

The unit digit of1!+2!+3!............+2019!​

Answer 1

Answer:

The required unit digit is 3

Step-by-step explanation:

The unit digit of1!+2!+3!............+2019!​

From 5! onwards for all n! the unit digit is zero.

Hence the contribution to the unit digit is through 1!+2!+3!+4! only which is 1+2+6+24=33.

Therefore the required unit digit is 3