Free Comparing Quantities Subjective Test 02 Practice Test - 7th grade
Question 1
Are these ratios equivalent? [1 MARK]
4 drivers : 1 hour
20 drivers : 5 hours
SOLUTION
Solution :
4 drivers: 1 hour
⇒ 4 : 1
20 drivers: 5 hours
⇒ 20 : 5 ⇒ 4 : 1
∴ Given ratios are equivalent.
Question 2
Dylan drew 1 heart, 1 star, and 26 circles. What is the ratio of circles to hearts? What is the ratio of hearts to star? [2 MARKS]
SOLUTION
Solution :Each answer: 1 Mark
Given that,
Number circles = 26
Number of hearts = 1
Number of stars=1
∴ Number of circles: number of hearts
⇒ 26 : 1
∴ Number of hearts: number of stars
⇒ 1 : 1
Question 3
Convert the ratios 5:4 and 9:25 into a percentage. [2 MARKS]
SOLUTION
Solution :Each Ratio: 1 Mark
Given ratio is, 5:4
⇒54
=54 x 2525
=125100
=125 %
Now,
9:25=925 x 44
=36100
=36%
Question 4
In a school, there were 860 students, 35% study Sanskrit. How many students do not study Sanskrit?
[2 MARKS]
SOLUTION
Solution :Steps: 1 Mark
Answer: 1 Mark
Total number of students = 860
Number of students who study Sanskrit = 35%
Therefore, number of students who do not study Sanskrit =100% - 35% = 65%
∴ Number of students not studying Sanskrit,
=65100×860=559
So, 559 students do not study Sanskrit.
Question 5
The marked price of a watch is ₹ 1250 and the shopkeeper allows 6% of discount on it. Find the selling price of the watch.
[2 MARKS]
SOLUTION
Solution :Formula: 1 Mark
Answer: 1 Mark
Given that,
Marked Price of the watch = ₹ 1250.
6% discount on MP
⇒6100×1250=₹ 75
SP = MP - Discount.
SP = ₹ 1250 - ₹ 75.
SP = ₹ 1175.The selling price of the watch is ₹ 1175.
Question 6
Nishu saves ₹ 120 from her pocket money. If she saves 10% of her pocket money, what is her pocket money? [3 MARKS]
SOLUTION
Solution :Concept: 1 Mark
Steps: 1 Mark
Answer: 1 Mark
Let Nishu's pocket money be n
Given, she saves 10% of her pocket money.
⇒ 10% of n = ₹ 120
⇒10100×n=120
⇒n=120×10010
⇒n=1200
So, Nishu's pocket money is ₹ 1200.
Question 7
Arun bought a car for ₹ 3,50,000. Next year, the price went up to ₹ 3,70,000. What was the percentage of price increase?
[3 MARKS]
SOLUTION
Solution :Formula: 1 Mark
Steps: 1 Mark
Answer: 1 Mark
Given that,
Original price = ₹ 3,50,000.
New price = ₹ 3,70,000.
Increase in the price = ₹ 3,70,000 - ₹ 3,50,000.
∴ Increase in the price = ₹ 20,000
Percentage increase=Increase in the priceoriginal price×100
Percentage increase=20000350000×100
Percentage increase=5.714%
The price of the car went up by 5.714%
Question 8
If number ‘n’ is increased by 25%, then it is decreased by 20%. What is the net percentage change in the value of n? [3 MARKS]
SOLUTION
Solution :Formula: 1 Mark
Steps: 1 Mark
Answer: 1 MarkGiven,
The number 'n' is first increased by 25%.
25So, the new value of n
=n + n×25100=n×54Now, the value of is again decreased by 20.
So, 20 of the new value
=n×54×20100=n×14So, the new value
=n×54 - n×14 = nNet percent change
=amount changedoriginal value×100Net change = n - n = 0.
So on substituting the values we get:
Percent change = 0n×100 = 0
So, there is no percentage change.
Question 9
Aju scored 70 in 1st test and 85 in 2nd test of Mathematics out of 100. What is percentage increase in marks scored by him?
[3 MARKS]
SOLUTION
Solution :Steps: 1 Mark
Application: 1 Mark
Calculation: 1 Mark
Marks scored in the 1st test = 70
Marks scored in the 1st test = 85
Increase in marks = 1st test mark - 2nd test marks
Increase in marks = 85 - 70 = 15
Increase in percentage
=(IncreaseOriginal marks)×100
Increase in percentage
=(1570)×100 = 21.42 %
Question 10
Amina buys a book for ₹ 275 and sells it at a loss 15%. How much does she sell it for? If she had sold it for ₹ 286 calculate the profit percent.
[4 MARKS]
SOLUTION
Solution :Concept: 1 Mark
Application: 1 Mark
Each Answer: 1 Mark
Given that
Amina bought a book for ₹ 275.
So the Cost price, CP = ₹ 275.
Loss%=15%
Loss=15% of 275
Loss=15100×275
Loss=4125100
Loss=41.25
Selling price=Cost price−Loss
Selling price=275−41.25
Selling price=₹233.75
Hence she sold it at ₹ 233.75.
If she has sold at ₹ 286,
The selling price, SP = ₹ 286
Profit = SP - CP
∴ On substituting the values we get, Profit = (286 - 275) = ₹ 11
Now, Profit % =profitCostPrice×100
Profit % =11275×100=4
∴ Had she sold it at ₹ 286 her profit% would have been 4%.
Question 11
A sum of ₹ 56000 gives ₹ 280 as interest in 2 years. Find the rate of interest. If the interest rate was 11%, then find the interest in two years. [4 MARKS]
SOLUTION
Solution : Formula: 1 Mark
Steps: 2 Marks
Answer: 1 Mark
Given,
Principal = ₹ 56,000
Time = 2 years
Interest = ₹ 280
Let the rate of interest be R % p.a.
S.I=P×R×T100
⇒R=I×100P×T
⇒R=280×10056000×2
⇒R=280560×2
⇒R=14=0.25
∴ The rate of interest is 0.25 % .
We have to find the interest if the rate of interest was 11 %,
Interest = P×R×T100
On substituting the values we get,
Interest = 56000×11×2100 = ₹ 12320
Hence, the interest in two years if the rate was 11% is ₹ 12320.
Question 12
Juhi sold a washing machine for ₹ 13,500 at the loss of 20%. Find the cost price of the washing machine. At what price she must sell to gain 20%?
[4 MARKS]
SOLUTION
Solution :Formula: 1 Mark
Steps: 2 Marks
Answer: 1 Mark
Given, Selling price = ₹ 13,500
Loss% = 20%
Let the cost price be x.
∴Loss = 20% of x
Selling price = Cost price - Loss
⇒13500 = x−20100×x
⇒13500 = x−15x
⇒13500 = 45x
⇒x = 16875
Therefore, she bought it for ₹ 16875.
So, cost price of the article = ₹ 16875
20% of the cost price
=20100×16875=₹3375
Net amount = 16875 + 3375 = ₹ 20250
So, in order to sell the washing machine at 20% profit, she needs to sell it at ₹ 20250.
Question 13
Find the amount to be paid at the end of 3 years of the sum of ₹ 1,200 at the rate of 12% p.a.
[4 MARKS]
SOLUTION
Solution :Formula: 1 Mark
Steps: 2 Marks
Answer: 1 Mark
Given,
Principal (P) = ₹ 1200
Rate (R) = 12% p.a.
Time (T) = 3 years
S.I.=P×R×T100
S.I.=1200×12×3100
S.I.=₹432
Total amount to be paid at the end of three years = P + S.I.
Amount = ₹ 1200 + ₹ 432
Amount = ₹ 1632
₹ 1632 has to be paid at the end of three years.
Question 14
If a shopkeeper incurs 10% loss and 25% profit on items sold for ₹ 45 and ₹ 40 respectively, then find his net profit/loss.
[4 MARKS]
SOLUTION
Solution :Application: 1 Mark
Steps: 2 Marks
Answer: 1 MarkLet the cost price of item sold at loss be ₹ x
⇒x−10 % of x=45
⇒x−10100×x=45
⇒x−110×x=45
⇒10x−x10=45
⇒x=50⇒Cost price is ₹ 50
⇒Loss = ₹ (50 - 45) = ₹ 5
Similarly, let the cost price of an item sold at profit be ₹ y.
⇒y+25 % of y=40
⇒y+25100×y=40
⇒y+14×y=40
⇒4y+y4=40
⇒y=32⇒Cost price is ₹ 32
⇒Profit = ₹(40 - 32) = ₹ 8
Net gain = ₹ (8 - 5) = ₹ 3
So, the shopkeeper makes a profit of ₹ 3.
Question 15
The population of a town 2 years ago was 62500. Since some people migrate to different cities the number of people decreases every year at the rate of 4% per annum. Find its present population. [4 MARKS]
SOLUTION
Solution :Formula: 1 Mark
Application: 1 Mark
Steps: 1 Mark
Answer: 1 Mark
Given that,
Population 2 years ago = 62500.
Rate of decrease = 4 % p.a.
For population 1 year ago,
P = 62500 , R = 4 %, T = 1 year
∴S.I=P×R×T100
⇒I=62500×4×1100
⇒I=2500
⇒ After 1 year the population will decrease by 2500 people
∴ Population 1 year ago is = 62500 - 2500 = 60,000
For present population,
P = 60,000, R = 4 %, T = 1 year
∴S.I=P×R×T100
⇒I=60000×4×1100
⇒I=2400
⇒ Present population = 60,000 - 2400 = 57,600
[We are subtracting the population because population is decreasing by 4% p.a.]
The present population is 57,600.