CRE 2 - Percentage Change | Percentage, Profit & Loss
The population of a town increases from 4200 to 5100. What is the approximate percentage increase?
- A.
10%
- B.
12%
- C.
25%
- D.
20%
- E.
21%
Answer: Option E
Explanation :
Percentage increase = = = 21.42 = approx 21%
Hence, option (e).
Workspace:
A number increases by 40 when added to 20% of itself. The number is
- A.
200
- B.
60
- C.
80
- D.
320
Answer: Option A
Explanation :
Let the number be N.
Number increases by 40 due to 20% of itself.
⇒ 20% of N = 40
⇒ 20/100 × N = 40
⇒ N = 200.
Hence, option (a).
Workspace:
A positive number was by mistake divided by 6 instead of being multiplied by 6. What is the % error on the basis of correct answer?
- A.
3
- B.
97
- C.
17
- D.
83
Answer: Option B
Explanation :
Let x be the unknown positive number. Then, correct answer = 6x
Wrong answer = x/6
Error = 6x – x/6 = 35x/6
With respect to correct answer, % error can be found as, = = 97%
Hence, option (b).
Workspace:
A candidate who gets 30% of the marks fails by 50 marks. But another candidate who gets 45% marks gets 25 marks more than necessary for passing. Find the number of marks for passing:
- A.
150
- B.
200
- C.
250
- D.
275
Answer: Option B
Explanation :
Let aggregate score be M and pass marks be x.
Then, by conditions of the problem, 0.3M = x – 50,
and, 0.45M = x + 25
Solving these simultaneous equations we get x = 200 marks
Hence, option (b).
Workspace:
Two numbers are 50% and 60% less than a third number. How much per cent is the second number less than the first?
- A.
15%
- B.
20%
- C.
10%
- D.
25%
Answer: Option B
Explanation :
Let the third number be x
Then, first number = 0.5x and second number = 0.4x
Second number is less than first by (0.5x – 0.4x) i.e. 0.1x
In terms of %age: 0.1x/0.5x × 100 = 20%
Hence, option (b).
Workspace:
A student needs 40% marks to pass in an exam. He got 240 marks and failed by 40 marks. Find the total marks?
- A.
700
- B.
800
- C.
400
- D.
300
- E.
None of these
Answer: Option A
Explanation :
Let total marks = x
∴ Pass marks = 40% of x
Also pass marks = 240 + 40 = 280
∴ 40% of x = 280
x = 280/(40%) = 700
Hence, option (a).
Workspace:
A earns 20% more than B but 25% less than C. If B earns Rs. 900 less than C, find the earnings of C :
- A.
Rs. 2500
- B.
Rs. 1600
- C.
Rs. 1500
- D.
Rs. 2400
Answer: Option D
Explanation :
Let the earnings of C be 'c'.
⇒ Earnings of A = 25% less than earnings of C = 3/4 × c
⇒ Earnings of A = 20% more than earnings of B
⇒ 3/4 × c = 6/5 × earnings of B
⇒ Earnings of B = 5/8 × c
Givne, c - 5/8 × c = 900
⇒ 3/8 × c = 900
⇒ c = 2400
Hence, option (d).
Workspace:
After 38 litres of petrol were poured into an empty tank, it was still 5% empty. How much petrol more must be poured into the tank in order to fill it?
- A.
38 liters
- B.
40 liters
- C.
38.5 liters
- D.
2 liters
Answer: Option D
Explanation :
Let the capacity of tank be C liters
Then, 0.95 C = 38 liters
∴ C = 38/0.95 = 40 liters
Now, (40 - 38=) 2 liters of petrol must be poured to fill the tank.
Hence, option (d).
Workspace:
If 17% is lost in grinding wheat, a country has to import 6 lakhs tonnes of wheat but can maintain from its resources if only 5% is lost in grinding. The quantity of wheat grown in the country is
- A.
5000 tonnes
- B.
50,000 tonnes
- C.
5,00,000 tonnes
- D.
50,00,000 tonnes
Answer: Option D
Explanation :
Let x lakh tones wheat is produced in the country.
When 17% of it is lost in grinding, the country needs to import 6 lakhs tonnes.
⇒ Consumption of wheat (in lakh tones) = 0.83x + 6 ...(1)
When 5% of it is lost in grinding, the country does not need to import.
⇒ Consumption of wheat = 0.95x ...(2)
From (1) and (2)
0.83x + 6 = 0.95x
⇒ 0.12x = 6 or
x = 50 lakh tonnes = 50,00,000 tonnes
Alternately,
Due to saving (17 - 5 = ) 12% of wheat produced, the country need not import 6 lakh tones of wheat.
⇒ 12% of Wheat produced = 6 lakh tones
⇒ 12/100 × Wheat produced = 6 lakh tones
⇒ Wheat produced = 50 lakh tones
Hence, option (d).
Workspace:
In a town, there are 3000 men and 3000 women. If men increased by 20% and women decreased by 40%, women as a percent of men now is:
- A.
50%
- B.
66.66%
- C.
80%
- D.
83.33%
- E.
None of these
Answer: Option A
Explanation :
After 20% increase, men = 3000 × 1.2 = 3600
After 40% decrease, women = 3000 × 0.6 = 1800
So women as a percentage of men =1800/3600 × 100 = 50%
Hence, option (a).
Workspace:
A 'laddoo' is made of 60% flour, 20% sugar and the rest is 'ghee'. What is the quantity of 'ghee' in two kg laddoos?
- A.
400 gms
- B.
2 kgs
- C.
100 gms
- D.
450 gms
- E.
None of these
Answer: Option A
Explanation :
If 60% is flour, 20% is sugar. So ghee = (100 - 60 - 20) = 20%.
So quantity of ghee in 2 kg laddoos = 20% of 2000 gms = 400 gms.
Hence, option (a).
Workspace:
If A's income is 50% more than B's, then B's income is what percent of A's income?
- A.
66.66%
- B.
80%
- C.
90%
- D.
125%
- E.
None of these
Answer: Option A
Explanation :
A’s income = 1.50 of B’s income = 3/2 × B’s income
B’s income = 2/3 of A’s income = 66.66% of A’s income.
Hence, option (a).
Workspace:
If the numerator of a fraction is increased by 50% and denominator decreased by 20%, the new value is 3/10. What was the original fraction?
- A.
3/5
- B.
4/5
- C.
7/8
- D.
3/2
- E.
None of these
Answer: Option E
Explanation :
Let the original fraction = x/y
∴
⇒
⇒ x/y = 4/25
Hence, option (e).
Workspace:
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