$\begin{align}  & \text{If }r\text{ varies inversely as the square root of }s\text{ and }t\text{ how does }s\text{ vary with }r\text{ and }t. \\ & (A)\text{ }s\text{ varies directly as }r\text{ and }t \\ & (B)\text{ }s\text{ varies inversely as }r\text{ and }{{t}^{2}} \\ & (C)\text{ }s\text{ varies inversely as }{{r}^{2}}\text{ and }t \\ & (D)\text{ }s\text{ varies directly as }{{r}^{2}}\text{ and }{{t}^{2}} \\\end{align}$

$\begin{align}  & P\text{ varies jointly as }m\text{ and }u,\text{ varies inversely as }q.\text{ Given that }p=4,\text{ }m=3\text{ } \\ & \text{and }u=2\text{ when }q=1,\text{find  the value of }p\text{ when }m=6,u=4\text{ and }q=\tfrac{8}{5} \\ & (A)\text{  }\tfrac{128}{5}\text{  (B) }15\text{  (C) 10  (D)  }\tfrac{288}{5} \\\end{align}$

The angles of a polygon are given by x, 2x, 3x, 4x, and 5x respectively. Find the value of x

U is inversely proportional to the cube of V and U = 81 when V = 2. Find U when V=3

If  y varies directly as $\sqrt{n}$and y =4 when n =4,   find y when $n=1\tfrac{7}{9}$

Find the value of x at the minimum point of the curve $y={{x}^{3}}+{{x}^{2}}-x+1$

T varies inversely as the cubes of R, when R =3, T = $\tfrac{2}{81}$, find T when R = 2

If x varies directly as square root of y and x = 81 when y =9, find x when y = $1\tfrac{7}{9}$

If x is inversely proportional to y and x = 2½ when y = 2, find x if y = 4

If y varies directly as the square root of x and y =3 and x =16. Calculate y when x = 64