Direct, Inverse, Joint Variations

What type of variation does this scenario represent?
The outside temperature
and the number of layers of clothes you need to wear outside to feel comfortable 

• direct variation

• inverse variation

• joint variation

• none of these

What type of variation does this scenario represent?
You and some friends decide to buy 2 pizzas and split the cost evenly.
The number of friends who are sharing the cost of the pizzas
and the amount of money you pay for your share.

• direct variation

• inverse variation

• joint variation

• none of these

Which of the following represents direct variation?

• y = kx

• y = k/x

• y = x/k

• y = mx + b

Which of the following represents indirect variation?

• y = kx

• y = k/x

• y = x/k

• y = mx + b

Given that y varies inversely with x, if x =7 and y = 4, what is y when x = 2?

• 14

• 10

• 2

• -14

If y varies inversely as x, and y = 32 when x = 3, find x when y = 15.

• 3/5

• 8/5

• 16/5

• 32/5

x and y are in inverse variation

x=6 and y=7

Given y=k/x... Find k

Mathematical Equivalence

ON

Does the equation show an inverse variation? 
y=10/x

• yes

• no

If the both quantities are increasing or decreasing then its called as

• Direct Variation

• Inverse Variation

If x varies inversely as the square root of y, and x = 9 when y = 121, find x when y = 81. (a)  

• 7

• 11

• 13

• 17