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 pound force is required to keep a 2750 pound car, travelling at a speed of 35 mph, from skidding on a curve of radius 550 feet. How much pound-force is then required to keep a 3600 pound car, travelling at a speed of 50 mph, from skidding on a curve of radius 750 feet?

In the figure, PT is a tangent. If TP = 12 cm, PB = x + 7 cm and PA = x cm, then find the value of x.

Study the given table and answer the question that follows.

The table shows the marks distribution among the students in a class.

Marks	No. of Students
Less than 10	2
Less than 20	5
Less than 30	6
Less than 40	8
Less than 50	10

How many students scored more than 40 marks?

A sum of money at simple interest amounts to ₹1,200 in 3 years and to ₹1,350 in 4 years. The sum is: