Home » Ask & Discuss » Mathematics. » Algebra « Back to Discussion

Algebra

Blazing goIITian

Joined:	19 Mar 2007
Post:	585

1 Jan 2008 22:41:07 IST

0 People liked this

278

how many no. of 7 digits are there such that sum of digits

None

how many no. of 7 digits are there such that sum of digits is always even.

Share this article on:

Comments (1)

sibendu dey

New kid on the Block

Joined: 30 Aug 2007

Posts: 15

1 Jan 2008 23:17:07 IST

Like 1 people liked this

HELLO SHUBHAM .....A VERY HAPPY NEW YEAR TO U...
THERE ARE 7 PLACES
IF WE CONSIDER THE FIRST SIX PLACES.............
TAT COULD BE FILLED IN 9*10*10*10*10*10
BUT OF THESE ...TWO CASES ARISE....
FIRST IF THE SUM OF DIGITS IN FIRST SIX PLACES IS ODD...THEN THE LAST PLACE COULD BE FILLED IN 5 WAYS....
SIMILARLY IF IT IS EVEN.........THEN THE LAST PLACE COULD BE FILLED IN 5 WAYS.....
SO TOTAL NO .....OF NOS....=9*10^5*5*2

PLZ TELL ME WHETHER IM WRONG OR NOT.....

Quick Reply

Reply

	Some HTML allowed.
	Keep your comments above the belt or risk having them deleted.
	Signup for a avatar to have your pictures show up by your comment
	If Members see a thread that violates the Posting Rules, bring it to the attention of the Moderator Team