TCS
Company
Find the last non zero digit of 96!.
a) 2 b) 4 c) 6 d) 8
Read Solution (Total 11)
-
- there is a technique..
z(96/5)*z(6)
=z(19)*z(6)
=last digit of 19!*last digit of 6!(non zero=
8*2=16
so last non zero digit =6 - 12 years agoHelpfull: Yes(8) No(3)
- how?
pls xplain.dnt know thw procedure.. - 12 years agoHelpfull: Yes(7) No(1)
- split the number as 5's multiple
96=5(19)+1
last digit of(2^19*last non zero digit of 19! * last non zero dig of 1!)
=6 - 12 years agoHelpfull: Yes(3) No(2)
- answer is 6
Z(n) denotes the last non zero digit in n!
Z(n) = {4 if tens digit is odd and 6 if tens digit is even) *
Z(n/5) * z(Units digit). - 12 years agoHelpfull: Yes(1) No(6)
- HOWW.
dont understand..
- 12 years agoHelpfull: Yes(1) No(0)
- ans will be 4
- 12 years agoHelpfull: Yes(1) No(0)
- ans is 4....
6*d(96/5)*d(6)=6*d(13)*2
=6*d(2)*2
=6*2*2
=4 - 12 years agoHelpfull: Yes(1) No(5)
- general procedure to find non zero digit in n!
let Z(n) denotes the last non zero digit in n!
Z(n) = {4 if tens digit is odd and 6 if tens digit is even) *Z(n/5) * z(Units digit).
sol:
Z(96) = 4 * Z(96/5) * Z(6)
= 4 * z(19) * last non zero digit of 6!
= 4 * last non zero digit of 19! * last non zero digit of 6!
= 4 * 2 * last non zero digit of (720)
{z(19)=4*z(19/5)*z(9)
=4 * last non zero digit of 3! * last non zero digit of 9!
=4*6*last non zero digit of (362880)
=4*6*8
192
i.e. 2}
=4*2*2
16
i.e. 6 is the ans :)
= 4 * 4 * 2
= 16 * 2
= 32 (answer is the last digit ie 2)
= 2
- 12 years agoHelpfull: Yes(1) No(1)
- answer is 6..
- 12 years agoHelpfull: Yes(0) No(3)
- explain clearly
- 12 years agoHelpfull: Yes(0) No(1)
- http://adityasrmca.co.cc/
- 12 years agoHelpfull: Yes(0) No(2)
TCS Other Question