GCSE Maths | Direct and Inverse Proportion

• if x and y are in direct proportion, then y = kx
• if x and y are in inverse proportion, then y = k/x

Question 1

• Example
• A = kB
• 12 = k x 3
• k = 12/3
• k = 4
• A = 4B

Inverse proportion example (question 1)

• T = k/N
• 30 = k/5
• k = 30 x 5
• k = 150
• T = 150/ N