Question
A shopkeeper sells a luxury watch at a markup price,
which is (100/3)% above its cost price. Had he purchased the watch for Rs. 300 more and sold it after giving a 10% discount on its previous marked price, he would have neither gained a profit nor incurred a loss. Now, if the shopkeeper aims to earn a 45% profit on the original cost price, find the selling price of the watch.Solution
ATQ, Let the cost price of the luxury watch be Rs. '3a' So, the marked-up price of the luxury watch = '3a' + '3a × (1/3) = Rs.'4a' [(100/3)% = 1/3 ] New cost price of the watch = Rs. (3a + 300) New selling price of the watch = Rs.(90/100) × 4a = Rs. '3.6a' For no profit and no loss, cost price of the watch = selling price of the watch So, 3a + 300 = 3.6a Or, 0.6a = 300 So, a = 500 Required selling price = 1.45 × 3 × 500 = Rs. 2175
Match the following machines with their working principles:
(i) Electric motor -Â (a) Heat energy into mechanical energy
(ii) Steam engin...
A cube of side a encloses a point charge q at its center. What is the electric flux through one of its faces?
A ray of light travels from glass (n=1.5) to air (n=1). For which angle of incidence will the ray just graze the surface (total internal reflection limit)?
Who laid the foundations of Quantum Theory?
An object moves towards a convex lens of focal length 20 cm with a velocity of 5 cm/s. When the object is at 30 cm from the lens, find the rate at which...
Which device is best suited for measuring the temperature inside metallurgical furnaces?

In a diatomic gas at ordinary temperatures, how many degrees of freedom contribute to internal energy?
In which type of motion does the velocity of a body vary with time?
Angle of friction and angle of repose are