Cat Sudoku Level 240 Hint
Look for a region whose legal cells are squeezed by two or more neighboring rows. High-level puzzles often move through exclusion, not obvious singles.
Cat Sudoku Level 240 Strategy
Master Level 240 uses a 10x10 board with 10 colored regions. It starts without fixed cats, so the region shapes and no-touch rule do the work. Work from the tightest rows and regions before placing a cat.
Cat Sudoku Level 240 Solution
Solution cells: R1C4, R2C8, R3C3, R4C5, R5C7, R6C2, R7C9, R8C1, R9C10, R10C6.