Page 319 - Start Up Mathematics_7

Section B

Question number 11 to 17 carry 2 marks each.
11. Explain giving example whether multiplicative identity exists for integers or not.
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12. Represent 2 × diagrammatically.
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13. If a dozen bananas cost ` 36, find the cost of 8 bananas.
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14. Write four rational numbers equivalent to .
2 × 3 5 × 4 t 9 7
15. Simplify .
10 × t 3
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16. Subtract 2x – 3y + 11 from the sum of 2x – 3y + 7 and –5x – 7.

17. The sum of three consecutive positive even integers is 48. Find the numbers.

Section C

Question number 18 to 21 carry 3 marks each.
18. A building is 50 storey high. Each floor of the building is 6 m high. A lift moves 2 metres in every
3 seconds. How long will it take Saurabh to move from 4th floor to 26th floor?
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19. Steffi has 300 stamps of different countries. of the stamps are from the U.K., are from other European
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countries and the remaining are from India. How many Indian stamps are there in Steffi’s collection?

20. The cost of 3 tables and 2 chairs is ` 820. If the cost of the table is ` 40 more than the chair, find the
cost price of each.

21. In how many years will a sum of money triple itself at the rate of 20% per annum simple interest?

Section D

Question number 22 to 25 carry 6 marks each.
22. The denominator of a fraction is 5 times the numerator. If 2 is added to the numerator and subtracted
from the denominator, then the fraction reduces to 1. Find the original fraction.
23. 23 packets each containing 12 battery cells cost ` 1,932. Find the cost of 36 packets each containing
10 battery cells.
24. Three pieces of ropes measuring 0.3 km, 30 m and 30 cm respectively are joined end to end to form a
single rope. Find the cost of the single rope so formed if the cost of rope is ` 20 per metre.
25. The length of a rectangle is 4 cm less than thrice the width. When the length is increased by 7 cm and
the width is decreased by 2 cm, the perimeter equals 90 cm. Find the length and width of the rectangle.

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