71Try to use the parity. ie., O+O = E , O+E = O and E+E=E .
So take different cases, first include one Even and so on.
how many 4digit numbers are there whose sum of the digits is odd?
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6 Answers
711yes i did it in the same way.
i was getting 13140 ,could anyone confirm or just solve it once...........
1057@funkygp...there ain't exist 13140 4 digit numbers !!!! only 9000 4 digit numbers are there....and i think the answer shud be 4500...
262Hint : the sum of digits is odd or even depends only on the choice of last digit
Ans: 4500
3hmmm.
aditya is correct.
the pattern is very cool.
OEOEOEOEOE. for the numbers from 1000 to 1009.
then from 1010 to 1019, it is
EOEOEOEO.
so it flips. :)