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Mam in veer bala rastogi biology class 11,it is written that NATURAL SYSTEM OF CLASSIFICATION WAS PROPOSED BY JOHN RAY
Swasti Nagar
a year ago
no thats not right, please prefer a standard book otherwise you'll get confused
ok mam ,thank you !
Swasti Nagar
a year ago
😊
can u explain example 12 briefly...where did u substitute 21
1. Abhishek Khurana 6 times 99 percentiler in CAT

2. PERCENTAGES

3. Introduction Example 10. Two successive percentage change of 12.5% and x % results in 10% change . Find x? Solution: n1:n3 10:11(overall 10% change) n1:n2:n3 = 40:45:44 ( common factor of 8 and 10 is 40) So change 45-44/45-100/45-2.22%

4. Introduction Example 11. A student instead of increasing a number by 12, decreased the number by 12%.The answer differs from correct answer by what percentage?

5. Introduction Example 11. A student instead of increasing a number by 12.5% , decreased the number by 12.5%The answer differs from correct answer by what percentage? Solution: Suppose n-8k student response will be-7k Correct response will be 9k Student response /correct response-7/9 correct *7/9 student so answer differs by 2/9% 22.22%

6. Introduction Example 12. Because the price of the petrol is increased by 16.66% I was able to purchase 3 litres less in 126 find the increased price of the petrol(in rs/litre)?

7. Introduction Example 12. Because the price of the petrol is increased by 16.66% I was able to purchase 3 litres less in 126 find the increased price of the petrol(in rs/litre)? Solution: price 6 7 Quantity x X-3 x/x-3 6/7 so --21 7k*18(21-3) -1260 k-70(increased price)

8. Introduction Example 13. In a group number of men are 20% more than no of women"62.5% of the men are literate . Of the total literates,33.33% are women . What percentage of women are literate?

9. Introduction Example 13. In a group number of men are 20% more than no of women.62.5% of the men are literate . Of the total literates,33.33% are women . What percentage of women are literate? Solution: women: men 5:6 40:48 literate(women :men)-15:30 (48*62.5/100-30 so x/30+x-1/3 wherex is the number of literate women) so literate woman= 1540 =37.5 %

10. Introduction Example 14. Fresh grapes contain 80% water, while dry grapes contain 10% water. If the weight of dry grapes is 500 kg, then what is its total weight when it is fresh?

11. Introduction Example 14. Fresh grapes contain 80% water, while dry grapes contain 10% water. If the weight of dry grapes is 500 kg, then what is its total weight when it is fresh? Solution: weight of dry grapes = 500 kg Since dry grapes contain 10% of water, weight of grape pulp in 500 kg of dry grapes 90% of 500 450 kg Let x be its total weight when it is fresh. Fresh grapes contain 80% water. Therefore, 20% of x is 450 kg => 100% of x = 450 5 = 2250 -x 2250 kg

12. Introduction Example 15. Out of the shirts produced in a factory, 15% are defective, while 20% of the rest are sold in the domestic market. If the remaining 8840 shirts are left for export, then the number of shirts produced in the factory is

13. Introduction Example 15. Out of the shirts produced in a factory, 15% are defective, while 20% of the rest are sold in the domestic market. If the remaining 8840 shirts are left for export, then the number of shirts produced in the factory is Solution: Let total shirts produced 100x Defective 15x Rest 85x Shirts sold in domestic market 17x Remaining shirts = 68x So,68x 8840 100x 13000.

14. Introduction Example 16. In a village, the production of food grains increased by 40% and the per capita production of food grains increased by 27% during a certain period. The percentage by which the population of the village increased during the same period is nearest to

15. Introduction Example 16. In a village, the production of food grains increased by 40% and the per capita production of food grains increased by 27% during a certain period. The percentage by which the population of the village increased during the same period is nearest to Solution: Required percentage is (40/127-1) * 100 10%

16. Introduction Example 17. The number of votes not cast for the PNC Party increased by 25% in the National General Election (NGE) as compared to the previous Assembly Polls, and as a result the PNC Party lost In the NGE try a majorlty of twice as many yotes by which it had won the Assembly Polls. If the total of 2,60,000 people voted each time, then how many of them voted for the PNC Party in the previous Assembly Polls?

17. Introduction Example 17. The number of votes not cast for the PNC Party increased by 25% in the National General Election (NGE) as compared to the previous Assembly Polls, and as a result the PNC Party lost In the NGE try a majorlty of twice as many yotes by which it had won the Assembly Polls. If the total of 2,60,000 people voted each time, then how many of them voted for the PNC Party in the previous Assembly Polls? Solution: Total Votes 2,60,000 Let x voters voted against the party in the Assembly Poll. Then votes in favour 260000- Therefore, majority of votes by which party won in previous poll - 260000-x-x = 260000-2x Next year votes against the PNC party increased by 25% So, votes against the party in general election1.25 x And votes polled in favour of the party Total votes - votes against 260000 - 1.25x

18. Introduction Therefore, majority of votes by which party lost in general election 1.25x- (260000 1.25x) 2.5x - 260000 It is given that, PNC Party lost by a majority twice as large as that by which it had won the Assembly Polls, Therefore 2.5x-260000 = 520000-4X 6.5x 780000 x 1,20,000 Therefore, votes polled by the voters for the party in Assembly Polls for previous year = (2,60,000-x) = (2,60,000-1,20,000) = 1,40,000.

19. Introduction Example 18, Dipin's score is 15% more than that of Rafi and Rafi's score is 10% less than that of Chandar. If the difference between the scores of Dipin and Chandar is 14, then what is the score of Rafi?

20. Introduction Example 18, Dipin's score is 15% more than that of Rafi and Rafi's score is 10% less than that of Chandar. If the difference between the scores of Dipin and Chandar is 14, then what is the score of Rafi? Solution: Dipin's score 115/100 x Rafi's score Rafi's score =90/100 x chandar's score Let Chandar's score be I15/100 x 90/100 x-x=14 207/200 X-X-14 7x = 14 x 200 => X = 400 Rafi's score 90/100 x 400 360

21. Introduction Example 19.40% population of a village are women and the rest are men. 60% of the women and 45% of the men are above 30 years old. If the total population of the village is 20000, then what can be the maximum number of people in the village who are 30 years old?

22. Introduction Example 19.40% population of a village are women and the rest are men, 60% of the women and 45% of the men are above 30 years old. If the total population of the village is 20000, then what can be the maximum number of people in the village who are 30 years old? Solution: Total population = 20000 So, men and women in the village = 12000, 8000 Women above 30 years = 4800 Men above 30 years 5400 Number of person below or equal to 30 years 9800 20000 (4800 +5400)

23. Introduction Example 20. Ravi's present age is 50% of Charu's present age. If a few years ago Ravi's age was 33.33% of the Charu's age, then find out the percentage change in Ravi's age over the time.

24. Introduction Example 20. Ravi's present age is 50% of Charu's present age. If a few years ago Ravi's age was 33.33% of the Charu's age, then find out the percentage change in Ravi's age over the time. Solution: Suppose Ravi's present age is x Charu's present age 2x Suppose y years ago (2x-y) x 33.33%-(x-y) (2x -y)*1/3 x y 2x-y-3x-3y y years ago, Ravi's age was (x X/2) x/2 Hence, percentage change in Ravi's present age-- (x2/x/2) *100-100%

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