# Finding a number in this sudoku

I have been trying this sudoku for nearly 5 hours now but im unable to find any number further...If anyone could help me out i would be really grateful..

Note: The numbers in black are the prefilled numbers. The numbers in blue are the ones i have found out. The numbers written in small and grey are the possible numbers that can go in that particular box(as i have found out...there may be a mistake in that :) )

• Without giving away the complete solution: the 5 in the 3rd row must be either in the 7th or the 9th column. Whichever it is, we can exclude the 2nd row 7th column cell being a 5. The same logic can be used for other cells as well. Commented Jun 15, 2018 at 15:14
• I put it through my own Sudoku solver, and it needed to make a guess at this point (though it did some more eliminations like @elias suggested). My solver handles "level 2" techniques, such as hidden/naked pairs and x-wing, but doesn't do "level 3" techniques such as triplets or swordfish. So this at least shows that it is a tricky one and that you haven't overlooked something simple. Commented Jun 15, 2018 at 15:26
• Ahh yes thank you @elias and @ Jaap Scherphuis Commented Jun 16, 2018 at 3:29
• Maybe any of the advanced techniques in this answer (X-Wing, Swordfish, XY-Wing, Colouring, Remote Pairs, XY-Chain, Forcing Chains, etc.) helps to strike out some possible candidate-digits? Commented Jun 17, 2018 at 9:19