An investment doubles itself in 8 years at simple interest. What is the annual interest rate?

The perimeter of a rectangle is 40 meters. If its length is 12 meters, what is its area?

If x + y = 12 and xy = 32, what is the value of $x^2+y^2$?

A watch dealer bought a watch for Tk. 1600. At what price should he sell it to make a 17.5% profit?

A train 150 meters long running at a speed of 36 km/h to pass a pole?

If a product's price increases by 20% and then decreases by 20%, what is the net percentage decrease?

A coin is tossed and a die is rolled simultaneously . What is the probability of getting a Head and an even number?