A certain alloy contians 70% copper and rest zinc. In 20 kg of such alloy, Let's find how many kg of zinc is required.

The length and breadth of a rectangular hall is 30 m. and 18 m respectively. Let's find how many square tiles of side 3 dcm. will be required for floor of the hall.

An alloy contains 60% copper and 40% nickel. A piece of this alloy of mass 50 g is heated to 50^(@)C and than dropped into a calorimeter of water equivalent 10 g containing 40 g of water at 20^(@)C . Calculate the final temperature of the mixture. Specific heat of copper ="0.09 cal.g"^(-1).^(@)C^(-1) , and of nickel = "0.11 cal.g"^(-1).^(@)C^(-1)

I went to fish market with my elder brother. He bought fish for Rs. 877.50. If 1 kg of fish cost Rs. 175.50, let me find how many kgs of fish, my brother bought.

Due to the rise the price of sugar we decided to reduce the consumption of suger by 4% presently, we consume 625 gm of suger every day. Let's find by how many grams the consumption of suger is ruduced and also the amout of suger consumed each day now.

In 120 of mixed fertilize, the amount of urea and potash are 60% and 40% respectivley. Let's find an write, how many kgs of fertilizers of each type are present in the mixed fertilizer.

50 g of an alloy containing 60% copper and 40% nickel is dropped in 55 g of water at 10^(@)C , kept in a calorimeter of water equivalent 5 g. The final temperature becomes 20^(@)C . What was the initial temperature of the alloy? Specific heats of copper and nickel are "0.095 cal.g"^(-1).^(@)C^(-1) and "0.11 cal.g"^(-1).^(@)C^(-1) respectively.

6 persons can complete a work in 7 days. Let's find how many persons will be required to finish the work in 21 days. In matheatical language, the problem may be stated as

4 tractors are required to cultivate 360 bighas of land in 20 days, Let us find, how many tractors are needed to cultivate 1800 bighas of land in 10 days.

50 g of an alloy containing 80% copper and 20% silver is heated up to t_(1)=80^(@)C and then dropped in a calorimeter of water equivalent W = 10 g containing m = 90 g of water at t_(2)=20^(@)C . What will be the final temerature of the mixture ? Specific heat capacity of copper and silver are s_(c)=0.09" cal.g"^(-1).^(@)C^(-1) and s_(s)="0.15 cal.g"^(-1).^(@)C^(-1) respectively.