Diameter of wheel of a cycle is 21 cm. The cyclist takes 45 minutes to reach a destination at a speed of 16.5 km/hr. How many revolutions will the wheel make during the journey?
Rohit buys a ball for Rs 450 and sells it. Rohit gives two successive discount of 20% and 5% to the customer. What will be the selling price (in Rs) of the ball?