(;AB[rc]AB[qc]AB[pb]AB[qa]AW[ob]AW[nc]AW[pc]AW[pd]AW[qd]AW[rf]AW[rh]AW[pf]AB[rj]AB[qh]AB[ph]AB[ri]AB[pj]AW[qg]C[White to kill. If you find any correct variations I haven't covered, please tell me!]AB[oa]AW[mb]AB[na]AW[lc]AB[ld]AB[kc]AB[kd]AB[ic]AW[kb]AW[jb]AW[md]AB[ib]AB[he]AP[goproblems]
(;W[rb]
(;B[sb]
(;W[rd];B[ra]C[Black is alive.])
(;W[ra];B[rd]
(;W[re];B[sd]C[Black makes two eyes and is alive!])
(;W[sd]
(;B[se];W[re]C[Black is dead. Well done!RIGHT])
(;B[re]
(;W[qe];B[se]C[Black caotures the stone and lives!])
(;W[se]C[Black is dead and cannot escape. Well done!RIGHT])))))
(;B[rd]
(;W[qb];B[sb];W[pa]C[Ko is not good enough in this situation!])
(;W[sb];B[re];W[se]C[Black is dead. Good job! :-)RIGHT])
(;W[sd]
(;B[sb];W[ra];B[se];W[re]C[Black has only one eye. He is dead - good job!RIGHT])
(;B[ra];W[sb];B[se];W[re]C[Black is dead. Good!RIGHT])
(;B[re]
(;W[qe];B[sb]LB[ra:A]LB[se:B]C[A and B are miai, so black lives!])
(;W[se];B[sb];W[ra]C[Black has only one eye and cant escape. Well done!RIGHT])
(;W[qb];B[sb];W[pa]C[Ko is not good enough here!])))
(;W[ra]
(;B[sb];W[sd];B[se];W[re]C[Black is dead. Nice!RIGHT])
(;B[re];W[qb]C[Black is dead and won't be able to escape. Congratulations!])))
(;B[ra]
(;W[rd];B[sb]C[Black is alive!])
(;W[sb]C[Black can't make two eyes. Nice!RIGHT])))
(;W[sc];B[sb];W[rb];B[sd]LB[rd:B]LB[ra:A]C[A and B are miai, black lives!])
(;W[rd];B[rb]C[Black makes two eyes and is alive.])
(;W[sd];B[rb]C[Black is alive])
(;W[ra];B[rb]C[Black captures the white stone and makes two eyes.]))