PERCENTAGE

 When two times % increase/ decrease happens formula

𝑥∗𝑦
±x ±y ± 100 ( if ‘+’ means increase , if ‘-’ means decrease)
120
 If 20% increase them final value is 100 of original value
80
 If 20% decrease then final value is 100 of original value
Example: The population of a town is 2,50,000 for 1st year it is increased
by 20% and for 2nd year increase by 30%. find the population of the town
after 2 years?
Answer:
Method - 1
𝑥∗𝑦
±x ±y ± 100
20∗30
+20+30+ 100 = +56%
Final value is 100+56= 156% of 25000 = 3,90,000
Method - 2
120
At first 20% increase means 100
130
Then 30% increase means
100
120 130
250000 x 100 x 100 = 3,90,000
1
 To find 25% of a number multiply that number by 4
3
 To find 75% of a number which is 3 times 25% so multiply by 4
3
 To find 37.5% of number multiply by 8.
5
 To find 66.66% of number multiply by 8

PERCENTAGES QUESTIONS
1) what is 80% of 200
2) what is 200% of 80
3) What percent of 80 is 200?
4) What percent of 200 is 80?
5) 80 is what percent more or less than 200?
6) 25% of 24 + 25% of 32 – 44% of 25 =?
7) If X% of 465 is 623, find 465% of X + 60
8) 200 is how much percent more than 80?
9) The price of a petrol is increased by 20%. By how much % it should be
reduced to get back to original price?
10) The price of a cooking oil is increased by 33.33%. By how much % a family
should reduce its consumption such that the expenditure is constant?
11) The price of a rice is reduced by 25%. How many more Kgs a person will get if his
previous consumption is 39kg?
12) Hari spends 45% of his income on food, 25% on children's education and 80% of
the remaining on house rent. What percent of his income he is left with?
(a) 5% (b) 6% (c) 8.25% (d) 10%
13) George spends 10 % of his income on travel, 25% on food, 20% on house rent
and 15% on medical, and he is left with Rs.594/–. What is his income?
(a) 2010 (b) 1980 (c) 1680 (d) 1800
14) For the above data. What is the amount spent on medical expenses?
(a) 297 (b) 300 c) 500 (d) 420
15) By 16.67% decrease in the price of rice, people can buy 10kg more rice for
Rs.100. Find the original price of rice per kg.
16) Two students appeared at an examination. One of them secured 9 marks more
than the other and his marks was 56% of the sum of their marks. The marks
obtained by them are:
(a)39, 30 (b)41, 32 (c)42, 33 (d)43, 34
17) LPS cylinder costs from 664/- to 830/- what percentage of consumption should
be reduced so that the expenditure is constant?
18) The population of a town is 1,60,000 now, if it increases constantly by 10% every
year. What will be the population of the town after 3 years?
(a)39,300 (b)2,12,960 (c)2, 33,000 (d)3,34,123
19) The population of the town is 11,025 at present. If there is a constant increase
of 5% every year. What was the population before 2 years?
20) If the present population of a village is 32500 and after 2 years it increases to
49,972 then what is the rate of increase per year?
21) The present population of a town is 100000 it increases annually at the rate of
20% p.a. what will be the population after 2 years.
(a)144000 b) 120000 c) 115000 d) 140000 e) 180000
22) On decreasing the price of a colour TV by 30%, its sale is increased by 20%. The
increase or decrease in the expenditure is
a)4% decrease b) 16% increase c) 20% increase d) 20% decrease e) 16% decrease
23) The population of a town increases by 12% during first year and decreases by
10% during second year. If the present population is 50400, what is was 2 years
ago?
a) 40000 b) 35000 c) 50000 d) 60000 e) 65000
24) A candidate who scores 30% fails by 5 marks, while another candidate who
scores 40% marks gets 10 more than minimum pass marks. The minimum marks
required to pass is
a) 50 b) 70 c) 100 d) 150 e) 200
25) To a sugar solution of 6 L containing 25% sugar, 1.5L of water is added. The
percentage of sugar In the new solution is
26) The number of seats in a cinema hall is decreased by 8% and also the price of
the ticket is increased by 4 percent. What is the effect on the revenue collected?
27) In a library, 30% of the books are in History. 50% of the remaining are in English
and 40% of the remaining are in German. The remaining 4200 books are in
regional languages. What is the total number of books in the library?
28) A student multiplied a number by 3/5 instead of 5/3. What is the percentage
error in the calculation?
29) Fresh fruits contain 75% while dry fruits contain 20% water. If the weight of dry
fruits is 300 kg, what was its total weight when it was fresh?
30) There are 5000 students in a school. The next year it was found that the number
of boys and girls increased by 10% and 15% respectively making the total
number of students in school as 5600. Find the number of girls originally in the
school?
31) -------
32) In an election between two candidates, the winning candidate got 70% of the
valid votes and won by a majority of 9000 votes. If out of total votes polled 90%
votes are valid, then what is the total number of votes polled?
33) In an examination, 25% candidates failed in English and 35 % students failed in
Math.If 15 % candidates failed in both, what is the percentage of candidates
who passed in both the subjects?
34) If the price of sugar increases by 10%, by what percentage a housewife should
reduce the consumption of sugar so that expense is not increased?
35) If 16(2/3) % of a number is added to itself, the number becomes 1400. Find the
original number.
36) When the numerator is increased by 200%, and the denominator is increased
by 350%, the resultant fraction is 5/12. Find the original fraction.
37) Three candidates contested an election and received 1136, 7636 and 11628
votes respectively. What percentage of the total votes did the winning candidate
get?
38) A batsman scored 110 runs which included 3 boundaries and 8 sixes. What
percent of his total score did he make by running between the wickets?

Answer Key:
1)160 2)160 3)250 4)40 5)60 6)3 7)683 8)150 9)16.67 10)25
11)13kg 12)6 13)1980 14)297 15)2 16)C 17)20 18)B 19)10k 20)24
21)A 22)E 23)C 24)A 25)25 26) 27) 28) 29) 30)
31)---- 32)25K 33)55 34)9.09 35)1200 36)5/20 37)57 38)45.45