Question

$$6$$ note-books cost $$Rs\ 156$$, find the cost of $$54$$ such note-books.

Answer 1

$$Notebooks_1 : cost_1 :: Notebooks_2 : cost_2$$
$$6 : Rs\ 156 :: 54 : Rs\ x$$
$$\therefore x=\dfrac{156\times 54}{6}=Rs\ 1404$$