Case IWhen unit digit can be 1,3,5 or 7 & digit at thousand's place can be 1,2,3,4,5,6,7 or 8.
No. of ways digits can be filled are:
Total no’s
=7×8×7×4=1568Case IIWhen unit digit can be 9 & digit at thousand’s place can be 1,2,3,4,5,6,7 or 8.
No. of ways digits can be filled are:
Total no’s
=8×8×7×1=448Case IIIWhen unit digit can be 1,3,5 or 7 & digit at thousand's place can be 9.
No. of ways digits can be filled are:
Total no’s
=1×8×7×4=224∴ Number of odd digits between 1000 & 9999 with no
digit repeated
=1568+448+224 =2240