The force (in pound-force) needed to keep a car from skidding on a curve varies directly with the weight of the car (in pounds) and the square of its speed (in miles per hour [mph]) and inversely with the radius (in feet) of the curve. Suppose 6125 pounds force is required to keep a 2750 pound car, travelling at a speed of 35mph, from skidding on a curve of radius 550 feet. How much pound-force is then required to keep a 3600 pounds car, travelling at a speed of 50mph, from skidding on a curve of radius 750 feet?

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?