When a, b, and x are positive and If a > b, then

When a, b, and x are positive and If a < b, then

a:b = b:c, then

If x varies directly with y, then

If x varies inversely with y, then

If m and n are the values and a and b are the quantities of item 1 and item 2 respectively, and x is the weighted average of the two items, then

If there is a container with ‘a’ litres of liquid A and if ‘b’ litres are withdrawn and an equal amount of the mixture is replaced with another liquid B and if this operation is repeated ‘n’ times, then after the nth operation, Liquid A in the container equals

If p and q are quantities of the cheaper and dearer items, r and s are the prices of the cheaper and dearer items, and t is the average price when they are mixed, then