[Elita]

Thanks guys for your reply.

Answer is (C). But I don't understand the way you reach that.

Why do you subtract 1 from 2^6?

And the Q asks in how many ways can you solve ONE OR MORE QUESTIONS?
What does it mean - the ways to solve all 6 Questions, or just one + some more, but how many??

I am totally confused with this one... PLease, help