self Maths Puzzle

What will be the unit digit of
(1!+2!+3!+4!+5!+........................+99!) ?

Read Solution (Total 2)

ans is 3
after 4! it will always give 0 at unit place
1!+2!+3!+4!=33
so at unit place 3
12 years agoHelpfull: Yes(10) No(3)

1!+2!+3!+4!+5!+6!+.....+99!=1+2+6+24+120+720....
so except 1!,2!,3!,4! all elements will contain zero at unit digit. so 1+2+6+24=33
so unit digit will be 3
12 years agoHelpfull: Yes(6) No(0)

self Other Question

An=A(n-1)-A(n-2) where, An is the nth term in the sequence,n is an integer n>=3,A(1)=1,A(2)=1,.Calculate S(1000) where, S(1000) is the sum of 1st 1000 terms. which pattern should i prepare for tcs old or new???