Question

If a lamp post has half of its length in mud and 1/3 of its length in water then what fraction of its length is above the water

Answer 1

(1-1/2-1/3)=1/6
Part of lamp post above water = 1/6

Answer 2

Part of lamp above the water = Total length - length under mud - length under water

                                               = 1 - 1/2 - 1/3
                                               = 6/6 - 3/6 - 2/6
                                               = 1/6