By increasing the price of entry ticket to a fair in the ratio 9:13, the number of visitors to the fair has decreased in the ratio 7:4. In what ratio has the total collection increased or decreased?

Let cost of original ticket = Rs 9 and and number of visitors = 70

=> Original revenue = 9 $$\times$$ 70 = Rs 630

After increase in cost of ticket

New cost of ticket = Rs 13 and number of visitors = 40

=> New Revenue = 13 $$\times$$ 40 = Rs 520

Since, new revenue is less than original revenue, thus total collection has decreased.

$$\therefore$$ Decrease in total collection ratio = $$\frac{630}{520}$$ = 63 : 52

=> Ans - (C)