By increasing the price of entry ticket to a fair in the ratio 7:17, the number of visitors to the fair has decreased in the ratio 9:5. In what ratio has the total collection increased or decreased?

Let cost of original ticket = Rs 7 and and number of visitors = 90

=> Original revenue = 7 $$\times$$ 90 = Rs 630

After increase in cost of ticket

New cost of ticket = Rs 17 and number of visitors = 50

=> New Revenue = 17 $$\times$$ 50 = Rs 850

Since, new revenue is greater than original revenue, thus total collection has increased.

$$\therefore$$ Increase of total collection ratio = $$\frac{630}{850}$$ = 63 : 85

=> Ans - (C)