10 kilograms of water are boiled at 373K, at a pressure of 1.013 10^5 N/m² and converted into steam. The specific latent heat of vaporization of water is 539 kcal/kg. 1 L of water, on conversion into steam, occupies 1671 L. The mechanical equivalent of heat is 4186 J/kcal. Calculate (a) the energy supplied to the system (water) (b) the work done by the system (c) the change in the internal energy of the system. (4 marks)
1. Megha bought 10 note-books for RS.40 and sold them at RS. 4.75 per note-book. Find her gain percent.
2. A fruit-seller buys oranges at 4 for RS.3 and sells them at 3 for RS.4. Find his profit percent.
3. A man buys a certain number of articles at 15 for RS.112.50 and sells them at 12 for RS.108. Find :
(i) his gain as percent;
(ii) the number of articles sold to make a profit of RS.75.
4. A boy buys an old bicycle for RS.162 and spends RS.18 on its repairs before selling the bicycle for RS.207. Find his gain or loss as percent.
5. An article is bought from Jaipur for RS.4,800 and is sold in Delhi for RS. 5,820. If RS. 1,200 is spent on its transportations, etc.; find the loss or the gain as percent.
6. Mohit sold a T.V. for RS.3,600; gaining one sixth of its selling price. Find :
(i) the gain. (ii) the cost price of the T.V. (iii) the gain percent.
7. By selling a certain number of goods for 5,500; a shopkeeper loses equal to one tenth of their selling price. Find : (i) the loss incured
8. The cost price of an article is 4/5 times of its cost price. Find the loss or the gain as percent.
9. The cost price of an article is 4/5 times of its selling price. Find the loss or the gain as percent.
10. A shopkeeper sells his goods at 80% of their cost price. Find his percent gain or loses?
11. The cost price of an article is 90% of its selling price. What is the profit or the loss as percent?
12. The cost price of an article is 30 percent less than its selling price. Find, the profit or the loss as percent.
13 A shopkeeper bought 300 eggs at 80 paisa each. 30 eggs were broken in transit and then he sold the remaining eggs at one rupee each. Find, his gain or loss as percent.
14. A man sold his bicycle for RS. 405 losing one-tenth of its cost price. Find :
(i) its cost price; (ii) the loss percent.
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1. Amit bought a calculator for 960 and sold it for 1104. Find his gain and gain per cent.
2. Ankita bought a mobile phone for 7 2350 and sold it for ? 2538. Find her gain and gain per cent.
3. Ayush bought a bicycle for 6250 and had to sell it for * 5875. Find his loss and loss per cent.
4. Aman bought a computer for * 24000 and its accessories pack worth for 3 1750. He sold it all for 26780. Find his gain and gain per cent.
5. A man bought a refrigerator for * 35615 and paid * 125 on its transportation. He sold it for *33953. Find his gain or loss per cent.
