Basic problem, something for beginners. If you solve this you are at least 21 kyu :)
(;AB[fa]AB[fb]AB[fc]AB[gc]AB[hc]AW[ga]AW[hb]AW[ia]AW[jb]AW[ka]AB[la]AB[lb]AB[lc]AB[kc]AB[jc]AB[ic]AW[ea]AW[eb]AW[ec]AW[ed]AW[fd]AW[gd]AW[hd]AW[id]AW[jd]AW[kd]AW[ld]AW[md]AW[mc]AW[mb]AW[ma]C[Black to play and live.]AP[goproblems]
(;B[ib]C[Well done, black lives in seki!RIGHT])
(;B[gb];W[ib];B[ha]C[Black cannot win this ko as he cannot connect or approach at L18.])
(;B[kb];W[ib];B[ja]C[Black cannot win this ko :(]))