In a college, the ratio of boys to girls is 29 : 33 respectively. When 142 more boys join the college, this ratio becomes 21 :19. How many more girls should join the college to make the number of boys and girls equal?
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?