By increasing the price of entry ticket to a fair in the ratio 3:5, the number of visitors to the fair has decreased in the ratio 7:2. In what ratio has the total collection increased or decreased?

Let cost of original ticket = Rs 3 and and number of visitors = 70

=> Original revenue = 3 $$\times$$ 70 = Rs 210

After increase in cost of ticket

New cost of ticket = Rs 5 and number of visitors = 20

=> New Revenue = 5 $$\times$$ 20 = Rs 100

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

$$\therefore$$ Decrease in total collection ratio = $$\frac{210}{100}$$ = 21 : 10

=> Ans - (C)