Question

Let
an
be the nth term of an A.P. If sigma100(r=1) a2r = alpha
=alpha and then the common difference of the A.P.sigma100(r=1)a2r-1 = beta
then the common difference of the AP is.

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Answer 1

Answer:

It is because the bottom part is kept on fire which gives it a black colour.

The inner part also becomes black

sometime.

The outer part if cleaned thoroughly it won't be much black.