Chapter 9: Ratio and Proportion Exercise – 9.1
Question: 1
If x: y = 3: 5, find the ratio 3x + 4y: 8x + 5y.
Solution:
Question: 2
If x: y = 8: 9, find the ratio (7x - 4y): 3x + 2y.
Solution:
Question: 3
If two numbers are in the ratio 6:13 and their L.C.M is 312, find the numbers.
Solution:
Question: 4
Two numbers are in the ratio 3: 5. If 8 is added to each number, the ratio becomes 2: 3. Find the numbers
Solution:
Question: 5
What should be added to each term of the ratio 7: 13 so that the ratio becomes 2: 3
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Question: 6
Three numbers are in the ratio 2: 3: 5 and the sum of these numbers is 800. Find the numbers
Solution:
Question: 7
The ages of two persons are in the ratio 5: 7. Eighteen years ago their ages were in the ratio 8: 13. Find their present ages.
Solution:
Question: 8
Two numbers are in the ratio 7: 11. If 7 is added to each of the numbers, the ratio becomes 2: 3. Find the numbers.
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Question: 9
Two numbers are in the ratio 2: 7. 11 the sum of the numbers is 810. Find the numbers.
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Question: 10
Divide Rs 1350 between Ravish and Shikha in the ratio 2: 3.
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Question: 11
Divide Rs 2000 among P, Q, R in the ratio 2: 3: 5.
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Question: 12
The boys and the girls in a school are in the ratio 7:4. If total strength of the school be 550, find the number of boys and girls.
Solution:
Question: 13
The ratio of monthly income to the savings of a family is 7: 2. If the savings be of Rs. 500, find the income and expenditure.
Solution:
It is given that
The ratio of income and savings is 7: 2
Savings
2x = 500
So, x = 250
Therefore,
Income = 7 × 250 = 1750
Expenditure = Income - savings
= 1750 - 500
= Rs.1250
Question: 14
The sides of a triangle are in the ratio 1: 2: 3. If the perimeter is 36 cm, find its sides.
Solution:
Question: 15
A sum of Rs 5500 is to be divided between Raman and Amen in the rate 2: 3. How much will each get?
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Question: 16
The ratio of zinc and copper in an alloy is 7: 9. It the weight of the copper in the alloy is 11.7 kg, find the weight of the zinc in the alloy.
Solution:
Question: 17
In the ratio 7: 8. If the consequent is 40, what a the antecedent
Solution:
Given ratio = 7: 8
Consequent
8x = 40
x = 40/8
x = 5
antecedent = 7x = 7 × 5 = 35
Question: 18
Divide Rs 351 into two parts such that one may be to the other as 2: 7.
Solution:
Question: 19
Find the ratio of the price of pencil to that of ball pen, if pencil cost Rs.16 per score and ball pen cost Rs.8.40 per dozen.
Solution:
Question: 20
In a class, one out of every six students fails. If there are 42 students in the class, how many pass?
Solution:
Given,
One out of 6 student fails
x out of 42 students
16 = x/42
x = 42/6
x = 7
Number of students who fail = 7 students
No of students who pass =Total students - Number of students who fail = 42 – 7 = 35 students.