Ratio and proportion

Question 1

Inverse proportion equation

Answer 1

Y= A/X

Question 2

What is inverse proportion?

Answer 2

When two things are in inverse proportion, one increases as the other decreases.

Question 3

What does inverse proportion look like on a graph?

Answer 3

On the graph you can see as the value of x increases, the value of y decreases.

Question 4

How do you solve inverse proportion questions?

Answer 4

Times for one, then divide for all

Question 5

Direct proportion equation

Answer 5

Y= AX

Question 6

What is direct proportion?

Answer 6

Two things are in direct proportion if as one thing increases, the other increases as well.

Question 7

What does direct proportion look like on a graph?

Answer 7

When you plot two things in direct proportion on a graph, you get a straight line through the origin.

Question 8

How do you solve direct proportion questions?

Answer 8

Divide for one, then times for all

Question 9

How do you do proportional division?

Answer 9

Add up the parts, then divide to find one part, and finally multiply to find the amounts. E.g: Kim and Chris share £100 in the ratio 5:10. How much does Chris get? 5+10=15, 100/15=6.6, 6.6x10= £66

Question 10

Percentage change

Answer 10

Difference/original x 100

Question 11

Density formula

Answer 11

Density = mass/volume

Question 12

Speed time distance formula

Answer 12

Distance = speed x time 
Speed = distance/time
Time = distance/speed

Question 13

Formula for volume of a sphere

Answer 13

V= 43πr3