Q1Written answer
20% of 700 m is
(a) 560 m (b) 70 m (c) 210 m (d) 140 m
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Worked solution
Solution: –
(d) 140m
20% of 700 m
The above condition can be written as = (20/100) × 700
= 14000/100
= 140 m
NCERT Exemplar · Class 7 · Maths
Chapter 7: Comparing Quantities
Practice each question, then open the answer or worked solution.
Questions
70 questionsQ2Written answer
Gayatri’s income ₹ 1,60,000 per year. She pays 15% of this as house rent and 10% of the remainder on her child’s education. The money left with her is
(a) ₹136000 (b) ₹120000 (c) ₹122400 (d) ₹14000
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Worked solution
Solution: –
(c) ₹122400
From the question it is given that,
Gayatri’s income ₹ 1,60,000 per year
She pays 15% of this as house rent = 15% of ₹ 1,60,000
= (15/100) × 1,60,000
= ₹ 24000
10% of the remainder on her child’s education = 10% of remaining amount of her income
Remaining amount of her income = ₹ 1,60,000 – ₹ 24000
= ₹ 136000
Total amount of her child’s education = 10% of ₹ 136000
= (10/100) × 136000
= 1360000/100
= ₹ 13600
Then, money left with Gayatri = ₹ 1,60,000 – (₹ 24000 + ₹ 13600)
= ₹ 1, 60, 000 – ₹ 37,600
= ₹ 1,22,400
Q3Written answer
The ratio of Fatima’s income to her savings is 4 : 1. The percentage of money saved by her is :
(a) 20% (b) 25% (c) 40% (d) 80%
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Worked solution
Solution:-
(a) 20%
Let’s assume the ratio if Fatima’s income to her savings be 4y : 1y.
Then, the percentage of money saved by her is = (her savings/(income + savings)) × 100
= (1y/4y + y) × 100
= 100/5
= 20
Q4Written answer
0.07 is equal to
(a) 70% (b) 7% (c) 0.7% (d) 0.07%
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Worked solution
Solution:-
(b) 7%
0.07 = 7/100
Percentage = (7/100) × 100
= 7%
Q5Written answer
In a scout camp, 40% of the scouts were from Gujarat State and 20% of these were from Ahmedabad. The percentage of scouts in the camp from Ahmedabad is:
(a) 25 (b) 32.5 (c) 8 (d) 50
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Worked solution
Solution:-
(c) 8
From the question it is given that,
In a scout camp, 40% of the scouts were from Gujarat State
So, let us assume number of scouts in the camp be 100
Then, scouts from Gujarat = 40% of 100
= (40/100) × 100
= 4000/100
= 40
Now, 20% of scouts were from Ahmedabad = 20% of 40
= (20 /100) × 40
= 800/100
= 8
Therefore, the percentage of scouts in the camp from Ahmedabad is 8.
Q6Written answer
What percent of ₹ 4500 is ₹ 9000?
(a) 200 (b) ½ (c) 2 (d) 50
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Worked solution
Solution:-
(a) 200
Let us assume percentage be Q,
Then, Q% of ₹ 4500 is ₹ 9000
(Q/100) × 4500 = ₹ 9000
(4500Q/100) = ₹ 9000
45Q = ₹ 9000
Q = ₹ 9000/45
Q = ₹ 200
Q7Written answer
5.2 is equal to
(a) 52% (b) 5.2% (c) 520% (d) 0.52%
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Worked solution
Solution:-
(c) 520%
5.2 = (52/10) × 100
= (5200/10)
= 520%
Q8Written answer
The ratio 3 : 8 is equal to
(a) 3.75% (b) 37.5% (c) 0.375% (d) 267%
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Worked solution
Solution:-
(b) 37.5%
The ratio 3 : 8 = (3/8) × 100
= 300/8
= 37.5%
Q9Written answer
225% is equal to
(a) 9 : 4 (b) 4 : 9 (c) 3 : 2 (d) 2 : 3
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Worked solution
Solution:-
(a) 9 : 4
225% = (225/100)
Because, to remove the %, we have to divide the given number by 100.
= 9/4
Q10Written answer
A bicycle is purchased for ₹ 1800 and is sold at a profit of 12%. Its selling price is
(a) ₹ 1584 (b) ₹ 2016 (c) ₹ 1788 (d) ₹ 1812
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Worked solution
Solution:-
(b) ₹ 2016
From the question it is given that,
A bicycle is purchased for ₹ 1800
Bicycle is sold at a profit of 12%.
Its selling price is =?
We know that, Profit percent = (Profit/CP) × 100
12 = (Profit/₹ 1800) × 100
(12 × 1800)/100 = Profit
Profit = 12 × 18
Profit = ₹ 216
Then, Profit = SP – CP
216 = SP – 1800
SP = 216 + 1800
SP = ₹ 2016