Given that y is inversely proportional to x and y=30 when x=12, find the value of y when x=40.

Step 1: Understand the problem The problem states that y is inversely proportional to x. This means that as x increases, y decreases and vice versa. The relationship can be expressed as y = k/x, where k is the constant of variation.

Step 2: Find the constant of variation (k) We know that y = 30 when x = 12. We can substitute these values into the equation to find k. So, 30 = k/12. Solving for k gives k = 30 * 12 = 360.

Step 3: Find the value of y when x = 40 Now that we know k = 360, we can substitute x = 40 into the equation to find y. So, y = 360/40 = 9.

Therefore, when x = 40, y = 9.