Page 277 - ICSE Math 8

Self-Testing Exercise 2

RATIO, PROPORTION AND ARITHMETICAL PROBLEMS

1. 8 pipes can fill a tank in 2 h 20 min. How long will it take to fill the tank with the help of 7 pipes?

2. Akbar has ` 5, ` 2 and ` 1 coins in the ratio 2 : 3 : 4. If the total value of all the coins is ` 320, find the
number of coins of each type.

3. 10 men and 6 women can do a piece of work in 5 days and 12 men and 9 women can do the same work
in 4 days. In how much time can 7 men and 9 women finish the same work?

4. Two pipes A and B can fill an empty tank in 24 min and 48 min respectively. If both the pipes are opened
together, when should pipe A be turned off so that the tank is filled in 22 min?
5. A’s income is 30% more than B’s income. How much percent is B’s income less than A’s income?

6. A broker charged 7% of S.P. as his commission. If a house is sold for ` 2,40,600, find the commission
he got for the deal.

7. Mohan sold a board game at a profit of 5%. Had he sold it for ` 20 more, he would have made a profit
of 10%. What is the cost price of the board game?
8. Calculate the compound interest for the third year on ` 4,000 invested for 4 years at the rate of 10%
per annum.

9. Calculate the difference between the compound interest and simple interest on ` 8,000 in
2 years at 12% per annum.

10. The cost price of an article is 20% below the marked price. If the article is available at 12% discount
and its cost price is ` 2,800. Find:

(a) the marked price of the article

(b) the selling price of the article

(c) the profit per cent

11. Ricky has black and red cards in the ratio 3 : 5. If he adds 2 more black cards in his collection of 16
cards, what will be the new ratio of black and red cards?

12. Find the mean proportion between 9 and 49.

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