Question

let n=1! +4!+7!+.........+400!. Then ten's digit of n is:

Answer 1

6 is the no. at tens digit

Answer 2

Answer:

Step-by-step explanation:

1! + 4! + 7! + ........ + 400! = 1 + 24 + 5040 + .......

∴ digit in the 10 ^th place is 4+2=6∴