A bottle is full of dettol. One-third of it is taken out and then an equal amount of water is poured into the bottle to fill it. This operation is done four times. Find the final ratio of dettol and water in the bottle.
A cone is hollowed out of a solid wooden cube of side 7 cm. The diameter and height of the cone is same as the side of the cube. What is the volume of the remaining cube?
By increasing the price of entry ticket to a fair in the ratio 5:7, the number of visitors to the fair has decreased in the ratio 11:9. In what ratio has the total collection increased or decreased?