Percentage Calculation
Basic Concepts of Percentage
"Percent" means "per 100"
3% means 3 per 100, 25% means 25 per 100. 100% means all.
or, 3% = 3/100, 25%=25/100
How to calculate the percentage of a number?
Let's calculate 10% of 90
i.e. (10/100 ) * 90 = 9
NOTE-1
100% of a number x = x
50% of a number x = x/2
Ex : 100% of 2400 = 2400
50% of 2400 = 1200
10% of 2400 = 240
1% of 2400 = 24
NOTE -2 (LEARN THE PERCENTAGE & ITS FRACTION)
50% = 1/2, 25% = 1/4 etc.
OR
| Fraction | Decimal | Percent |
| 1/2 | 0.5 | 50% |
| 1/3 | 0.333... | 33.333...% |
| 2/3 | 0.666... | 66.666...% |
| 1/4 | 0.25 | 25% |
| 3/4 | 0.75 | 75% |
| 1/5 | 0.2 | 20% |
| 2/5 | 0.4 | 40% |
| 3/5 | 0.6 | 60% |
| 4/5 | 0.8 | 80% |
| 1/6 | 0.1666... | 16.666...% |
| 5/6 | 0.8333... | 83.333...% |
| 1/8 | 0.125 | 12.5% |
| 3/8 | 0.375 | 37.5% |
| 5/8 | 0.625 | 62.5% |
| 7/8 | 0.875 | 87.5% |
| 1/9 | 0.111... | 11.111...% |
| 2/9 | 0.222... | 22.222...% |
| 4/9 | 0.444... | 44.444...% |
| 5/9 | 0.555... | 55.555...% |
| 7/9 | 0.777... | 77.777...% |
| 8/9 | 0.888... | 88.888...% |
| 1/10 | 0.1 | 10% |
| 1/12 | 0.08333... | 8.333...% |
| 1/16 | 0.0625 | 6.25% |
| 1/32 | 0.03125 | 3.125% |
Q1. |
20% of a number x is 40 more than 30 % of 120. Find the value of x. |
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A. 320 |
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B. 420 |
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C. 480 |
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D. 380 |
Correct Option is D
Explanation:
30 % of 120 = 36
20% of a number x = 40 + 36 = 76
1/5 of x = 76
x = 76 * 5 = 380
Q2. |
What is 30 % of 40 % of 2400? |
Q3. |
Express 23/36 as a percentage. |
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A. 23% |
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B. 63 8/9 % |
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C. 23/3600 % |
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D. 23/1800 % |
Correct Option is B
Explanation:
Required percentage = 23/36 x 100 = 63 8/9 %
Q4. |
20% of 56 = 40% of x. Find the value of x. |
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A. 112 |
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B. 28 |
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C. 5.6 |
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D. 11.2 |
Correct Option is B
Explanation:
20% of 56 = 40% of x.
As 40 = 2 x 20
x must be half of 56 that is 28.
x = 28. (Ans)
We can get the answer by calculation also.
20/100 * 56 = 40/100 * x
x = (20 * 56)/ 40 = 28
Q5. |
Find 11 1/9 % of 90. |
Q6. |
Find 25% of 200. |
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A. 40 |
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B. 50 |
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C. 25 |
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D. 60 |
Correct Option is B
Explanation:
25% of 200
25/100 x 200
1/4 x 200 = 50
Q1. |
Ramesh owns 87.5% of a property. 12.5 % of the part of it he owns is worth 3.5 lakhs. Find the value of the property (In lakh ?) |
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A. 32 |
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B. 40 |
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C. 52 |
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D. 70 |
Correct Option is A
Explanation:
87.5% = 7/8
12.5 % = 1/8
Let the property value = x
7/8 × 1/8 × x = 3.5
x = 3.5 × 8 × 8 / 7 = 32 lakhs.
Q2. |
If a % of b + 4 % of ab = 15% of (a+b), then what is the value of 1/a + 1/b ? |
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A. 1/2 |
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B. 1/5 |
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C. 1/4 |
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D. 1/3 |
Correct Option is D
Explanation:
a % of b + 4 % of ab = 15% of (a+b)
ab/100 + 4 * ab/100 = 15 * (a+b) /100
5 * ab / 100 = 15 * (a+b) / 100
a + b / ab = 1/3
1/ a + 1/b = 1/3
Q3. |
p% of q + q% of p = 14 2/7 % of (p+q), then p+q/pq =? |
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A. 4% |
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B. 10% |
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C. 14% |
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D. 20% |
Correct Option is C
Explanation:
p% of q = pq/100
q% of p = pq/100
14 2/7% of (p+q) = 1/7 (p+q)
pq/100 + pq/100 = 2 pq/ 100
Hence 2 pq/ 100 = 1/7 (p+q)
Or, (p+q)/pq = 14/100 = 14%
Q1. |
If a, b, c, d are positive integers. Solve the question with the 4 statements given below. i) a % of (c + d) = 40 ii) a – b = 20 iii) b + c = 50 iv) a + b = (c + d)% of (a + b) To get the answer to find the percentage a of (b + c + d), which of the above statement is not required? |
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A. (i) |
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B. (ii) |
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C. (iii) |
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D. (iv) |
Correct Option is C
Explanation:
From statement (iv), we can get, c + d = 100
Putting the value of c + d in (i), we get, a = 40
Putting a = 40 in (ii) we get, b = 20
a / b+c+d x 100 = 40/120 =33.33%
We don't need statement (iii) to get the above answer.
Q2. |
If a, b, c, d are positive integers. Solve the question with the 4 statements given below. i) a % of (c + d) = 40 ii) a – b = 20 iii) b + c = 50 iv) a + b = (c + d)% of (a + b) What percent is a of (b + c + d)? |
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A. 14.28% |
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B. 25% |
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C. 33.33% |
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D. 10% |
Correct Option is C
Explanation:
From statement (iv), we can get, c + d = 100
Putting the value of c + d in (i), we get, a = 40
Putting a = 40 in (ii) we get, b = 20
a / b+c+d x 100 = 40/120 =33.33%;