Math Set - 21

1. (0.9 x 0.9 x 0.9 + 0.1 x 0.1 x 0.1) is equal to

a. 0.73  b. 0.82
c. 0.91  d. 1.00

2. By what least number should 4320 be multiplied so as to obtain a number which is a perfect cube?

a. 40  b. 50
c. 60  d. 80

3. In an examination, a student had to obtain 33% of the maximum to pass. He got 125 marks and failed by 40 marks. The maximum marks were

a. 500  b. 600
c. 800  d. 1000

4. If A:B = 3:4 and B:C = 8:9 then A:B:C is

a. 8:6:9  b. 9:8:6
c. 6:8:9  d. 3:32:9

5. If 30% of (B-A) = 18% of (B+A), then the ratio A:B is equal to

a. 4:1  b. 1:4
c. 5:4  d. 5:9

6. Two numbers are in the ratio 3:5 and their LCM is 225. The smaller number is

a. 45  b. 60
c. 75  d. 90

7. The difference between the selling price and cost price of an article is Rs. 210. If the profit percent is 25, then the selling price of the article is

a. Rs. 950   b. Rs. 1050
c. Rs. 1150  d. Rs. 1250

8. If the ratio of the cost price and the sale price of an article be 5:6, the percentage of gain is

a. 25  b. 20
c. 18  d. 15

9. An article, which is marked Rs. 650, is sold for Rs. 572. The discount given is

a. 12%  b. 13%
c. 21%  d. 26%

10. Two successive discounts of 10% and 5% are equivalent to a single discount of

a.14%    b. 14.25%
c.14.50% d. 15%

11. 32 is what percent of 80?

a. 24%  b. 25.6%
c. 36%  d. 40%

12. The length of a rectangular plot of land is increased by 5% and the breathe is decreased by 10%, how much will its area increase or decrease?

a. 6.5% increase b. 5.5% decrease
c. 5.5% increase d. 6.5% decrease

13. A alone can complete a work in 18 days and B alone in 15 days. B alone worked at it for 10 days and then left the work. In how many more days, will A alone complete the remaining work?

a. 5  b. 5.5
c. 6  d. 8

14. Tapas works twice as fast as Mihir. If both of them together complete a work in 12 days, Tapas alone can complete it in

a. 15 days  b. 18 days
c. 20 days  d. 24 days

15. The speeds of the two trains are in the ratio 6:7. If the second train runs 364 km in 4 hours, then the speed of first train is

a. 60 km/hr  b. 72 km/hr
c. 78 km/hr  d. 84 km/hr

16. Two trains, 80 meters and 120 meters long, are running at the speed of 25 km/hr and 35 km/hr respectively in the same direction on parallel tracks. How many seconds will they take to pass each other?

a. 48  b. 64
c. 70  d. 72

17. At some rate of simple interest, A lent Rs. 6000 to B for 2 years and Rs. 1500 to C for 4 years and received Rs. 900 as interest from both of them together. The rate of interest per annum was

a. 5%  b. 6%
c. 8%  d. 10%

18. A sum of money becomes double in 3 years at compound interest compounded annually. At the same rate, in how many years will it become four times of itself?

a. 4    b. 6
c. 6.4  d. 7.5

19. There are 50 students in a class. Their average weight is 45 kg. When one student leaves the class the average weight reduces by 100 gm. What is the weight of the student who left the class?

a. 45 kg.    b. 47.9 kg.
c. 49.9 kg.  d. 50.1 kg.

20. 30 pens and 75 pencils altogether were purchased for Rs. 510. If the average price of a pencil was Rs. 2, what was the average price of a pen?

a. Rs. 9   b. Rs. 10
c. Rs. 11  d. Rs. 12

Answers:-

1.(a) 2.(b) 3.(a) 4.(c) 5.(b) 6.(c) 7.(b) 8.(b)
9.(a) 10.(c) 11.(d) 12.(b) 13.(c) 14.(b) 15.(c) 16.(d)
17.(a) 18.(b) 19.(c) 20.(d)