The coach of a cricket team of M.K.Nagar High School buys 3 bats and 6 balls for Rs. 3900. Later he buys one more bat and 2 balls for Rs. 1300. Identify the unknowns in each situation. We observe that there are two unknowns in each case.

The cost of 1kg potatoes and 2 kg tomatoes was Rs. 30 on a certain day. After two days, the cost of 2 kg potatoes and 4 kg tomatoes was found to be Rs. 66.Identify the unknowns in each situation. We observe that there are two unknowns in each case.

Ravi wants to buy a bicycle. He goes to the market and finds that the bicycle of his choice costs Rs. 2,400. He has only Rs. 1,400 with him. To help, the shopkeeper offers to help him. He says that he can make a down payment of Rs. 1400 and pay the rest in monthly instalments of Rs. 550 each. Ravi can either take the shopkeepers offer or go to a bank and take a loan at 12% per annum simple interest. From these two opportunities which is the best one to Ravi. Help him.