If x and y are inversely proportional, then which of the following is correct?

The cost of 40 packets of 12 pens is ₹1680. The cost of 30 packets each containing 9 pens is

If x varies directly to y and if x = 3, y = 5, then find the value of y when x = 7.8.

The rate of advertisement on a TV channel is directly proportional to the duration of the advertisement. If the rate of an advertisement of 20 seconds is Rs. 1,25,000, then the rate of an advertisement of 25 seconds will be Rs. ________.

x varies inversely to the square of y. Given that y = 5 when x = 6, find the value of x when y = 4.

If x and y are inversely proportional, then which of the following is correct?

What will come in place of ‘A’ in the given equation?
​$$\frac{A}{192} = \frac{48}{A}$$​​

If x varies indirectly to y² and if x = 78, y = 11, then find the value of x when y = 2.2

y varies directly proportional to (x + 3) and y = 8 when x = 1. What is the value of y when x = 2?