Variation Lesson 2

Variation Lesson 2

1.1 Direct Variation

Multiple Choice

Which of the following uses the correct symbol to represent the correct joint variations. "m varies directly as n and p"

 $\propto$ 

•  $m\propto\frac{n}{p}$  

•  $m\propto np$  

•  $p\propto mn$  

Multiple Choice

 $r\ varies\ directly\ as\ \sqrt{s\ }\ and\ t^{2.}$  It is given tha r = 490 when s = 1.96 and t=5. Express r in terms of s and t. 

•  $r\ =\ 14\sqrt{s}t^2$  

•  $r\ =\ \frac{1}{14}\sqrt{s}t^2$  

•  $r=25.5\sqrt{t}s^2$  

•  $r=25.5\sqrt{s}t^2$  

Multiple Choice

 $It\ is\ given\ that\ r\propto st^3\ and\ r=384\ when\ s=9\ and\ t=4.$  Express r in the terms of s and t.

•  $r=\frac{3}{2}st^3$  

•  $r=\frac{2}{3}st^3$  

•  $\frac{8}{3}st^3$  

•  $\frac{3}{8}st^3$  

Multiple Select

 $It\ is\ given\ that\ y\propto x\sqrt{z}\ and\ y=84\ when\ x\ 21\ and\ z=25.$  Find the value of x when y=51.2 and z=256
Also, choose the correct equation where y is express in terms of x and z 

•  $y=\frac{4}{5}x\sqrt{z}$  

•  $y=\frac{5}{4}x\sqrt{z}$  

•  $x=4$  

•  $x=\frac{1}{4}$  

Multiple Select

Given e varies directly as the square root of f and the cube of g. If e=512 when f=16 and g=4, calculate the value of f when e=1 750 and g=5.
Also, choose the correct equation where e is expressed in terms of f and g.

•  $e=\frac{1}{2}\sqrt{f}g^3$  

•  $e=2\sqrt{f}g^3$  

• f = 49

• f = 7

Multiple Select

The total wages of a worker, RM G, varies directly as the square of the number of working hours, t in a day. He receives RM128 when working for 8 hours.

*G = 128, when t = 8

(i) Calculate the total wages if the worker works for 9 hours. 

(*Hint: G = ?, when t = 9)

(ii) What is the number of working hours if he receives the total wages of RM84.50? (*Hint: t = ?, when G = 84.50)

•  $G=18$  

•  $t=13$  

•  $G=162$  

•  $t=6.5$