You wouldn't belive how many times, I had this situation - In fact, I'm really sure it's a common one... And I never saw it played out correctly!
(Thanks to hello and Timko for the corrections!)
(;AW[db]AW[cb]AW[cc]AW[cd]AW[be]AW[ad]AB[ce]AB[bf]AB[dd]AB[dc]AB[eb]AB[fc]AB[cg]AB[de]C[Black to reduce white... :))]AB[fb]AP[goproblems]
(;B[ab]C[White will respond at B18. The rest but A17 are a mistake. A17 actually lets white chose betweena seki and a ko..]
(;W[bb]
(;B[af];W[ac]
(;B[bd]C[White'd take at A19. Taking at B17 is losing another point and is included to show what happens..];W[aa]
(;B[ae];W[ea];B[fa];W[da]C[Well done! ;)RIGHT])
(;B[da];W[ca]
(;B[ea];W[ae]C[This is worse than the correct solution by 2 moku.])
(;B[ae];W[ea];B[fa];W[da]C[Well done! ;)RIGHT])))
(;B[ae];W[bd];B[da];W[ca];B[ea]C[This is worse than the correct solution by a moku.])
(;B[da];W[ae];B[ca];W[ba];B[ea]C[This is worse than the correct solution by 2 moku.]))
(;B[ac];W[bc]
(;B[af];W[aa]
(;B[ae];W[bd];B[da];W[ca];B[ea]C[This is worse than the correct solution by 2 moku.])
(;B[da];W[ca]
(;B[ea];W[ae]C[This is worse than the correct solution by 3 moku.])
(;B[ae];W[bd];B[ea]C[This is worse than the correct solution by 2 moku.])))
(;B[da];W[aa]
(;B[af];W[ae]
(;B[ca];W[ba];B[ea]C[This is worse than the correct solution by 2 moku.])
(;B[ea];W[ca]C[This is worse than the correct solution by 3 moku.]))
(;B[ca];W[af];B[ag];W[ae];B[ea];W[ba]C[This is worse than the correct solution by 3 moku.]))))
(;W[bc];B[af]C[White would die.])
(;W[ba];B[da]
(;W[bb];B[ac];W[bc];B[af]C[White would die.])
(;W[bc];B[ac];W[bb];B[af]C[White would die.]))
(;W[da];B[ac];W[bb];B[ba];W[bc];B[af];W[aa];B[ae];W[ab];B[bd]MA[be]C[Would resualt in a ko..])
(;W[ac];B[ba]C[(Thanks to Timko for the correction of the following variation.)];W[bb];B[bd];W[bc];B[af];W[ca];B[ae];W[ea];B[fa];W[aa];B[da];W[bd];B[ea]C[This is worse than the correct solution by a moku. (Thanks Timko!)]))
(;B[da];W[bc]
(;B[ca];W[ba]
(;B[ea];W[af];B[ag];W[ae]C[This is worse than the correct solution by 3 moku.])
(;B[af];W[ea]
(;B[da];W[ae];B[fa];W[ca];B[ea]C[This is worse than the correct solution by 4 moku.])
(;B[fa];W[ae])
(;B[ae];W[bd]
(;B[fa];W[da]C[This is worse than the correct solution by 5 moku.])
(;B[da];W[ab];B[fa];W[ca];B[ea]C[This is worse than the correct solution by 2 moku.]))))
(;B[af];W[ae];B[ca];W[ba];B[ea]C[This is worse than the correct solution by 2 moku.]))
(;B[af];W[ab]
(;B[ae];W[bd];B[da];W[ca];B[ea]C[This is worse than the correct solution by 2 moku.])
(;B[da];W[ca]
(;B[ae];W[bd];B[ea]C[This is worse than the correct solution by 2 moku.])
(;B[ea];W[ae]C[This is worse than the correct solution by 3 moku.]))))