If two quantities x and y vary directly with each other, then :
Question 31
If the quantities x and y vary directly with each other, then___of their corresponding values remains constant.
Question 43
Two quantities x and y are said to vary directly with each other if for some rational number k, xy =k.
Question 54
When two quantities are related in such a manner that, if one increases, the other also increases, then they always vary directly.