Aruna cut a cake into two halves and cuts one half into smaller pieces of equal size. Each of the small pieces is twenty grams in weight. If she has seven pieces of the cake in all with her, how heavy was the original cake?

Both courses of action are not strong.

All are volatile except iron.

In all pairs except (d), first is used to contain the second.

All are the currencies of different Countries.

1/9 : 1/9² : : 1/13 : 1/13²

Second is obtained from the first .

We can write with pen, marker, pencil on paper. So, paper is defferent from others.