Page 140 - Start Up Mathematics_7

5. How do we calculate profit percent?

6. What should be added to the principal to get amount?

let’s evaluate

1. If 12.5% of q is 19, find the value of q.
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2. Find the number whose 6 % is 20.
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3. Find the time duration whose 60% is 300 minutes.
4. What percentage of 12 hours is 3 days?
5. What percentage is 200 mL of 3 litres?

6. Convert each of the following fractions to percentage:
2 1 17 5 11
(a) (b) 1 (c) (d) 1 (e)
3 4 500 8 250
7. Find:
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(a) 25% of 400 (b) 12 % of 102 (c) 0.05% of 1,000
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8. The strength of students enrolled for summer camp increases by 20% this year. The number
of students increased by 80. Find the number of students enrolled last year.
9. A certain sum of money doubles itself in 6 years. In how many years will it be three times at
the same rate of simple interest?

10. Shristi bought a house for ` 6,00,000. Later, she sold it for ` 9,00,000 to buy a new one. What
was the percentage increase in its value?

Thinking Skills

1. In an examination, Swadha secured 320 marks. If her aggregate is 80%, what is the maximum
possible marks out of which Swadha scored these marks?
2. In an election, a candidate got 40% of the total valid votes. 10% of the total votes were
declared invalid. If the total number of votes were 6,00,000, find the number of valid votes
polled in favour of the candidate.
3. By selling a mobile phone for ` 4,000, a person loses 15%. For what amount should he sell
it so that he gains 10%?

4. A sum of money amounts to ` 4,480 at 6% simple interest per annum at the end of 2 years.
Find the principal.
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5. Karan borrowed ` 1,500 from a financer. After 3 years he paid ` 2,655 to the financer and
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cleared the accounts. Find the rate of interest charged.

Values and Life Skills

1. Ridhima secured 333 marks out of 500 in her annual examination. Find the percentage of
marks obtained by her.
What are the factors which affect the result of a student?

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