If "–" stands for division, "+" stands for multiplication, "÷" stands for subtraction and "×" stands for addition, which of the following equations is correct?
A solid right circular cone of radius 4 cm and height 7 cm is put inside a cylindrical vessel of radius 5 cm and height 8 cm. How much water in cubic cm will be required to fill the cylindrical vessel completely?
In an army selection process, the ratio of selected to unselected was 5:1. If 100 less had applied and 20 less selected, the ratio of selected to unselected would have been 6:1. How many candidates had applied for the process?