Home Tuitions

Direct Variation Formula

About Direct Variation Formula

The relationship between two variables in which one is a constant multiple of the other is known as direct variation. When one variable affects the other, for example, they are said to be proportional. The equation b = ka is used when b is directly proportional to a. (where k is a constant). When two variables are coupled in such a way that the ratio of their values remains constant, they are said to be in direct variation. Direct variation can be stated in a variety of ways mathematically. Because the ratio of y to x never changes, y and x fluctuate directly in equation form. More Maths Formulas on the parent's page.

The formula for direct variation is: y ∝ x => y = kx

Solved Example of Direct Variation Formula

Example: The number of wooden blocks used determines the number of wooden boxes produced. A total of 120 wooden blocks are required for 30 boxes. How many wooden blocks does a box require?

Sol:

  • In the given problem,
  • Number of wooden blocks needed for 30 boxes = y = 120
  • Number of boxes = x = 30
  • Number of wooden blocks needed for a box = k
  • The direct variation formula is,
  • y = k × x
  • 120 = k × 30
  • k = 120/30
  • k = 4
  • Number of wooden blocks needed for a box = 4

Download the pdf of the Direct Variation Formula