Important Questions on Proportional Reasoning - 1 for Class 8

Important Questions on Proportional Reasoning - 1 for Class 8 are available in this Maths article. Important Questions on Proportional Reasoning - 1 for Class 8 are very useful to solve the problems easily. This article helps the students to know the key questions and answers about Proportional Reasoning. Proportional reasoning helps us compare quantities and understand how one value changes in relation to another, which we use in everyday calculations. Our subject experts have provided detailed solutions for these problems based on the CBSE syllabus and the NCERT textbook. This material helps students revise the chapter easily and perform well in the final examination.

Table of Contents

• Exercise 1: Ratio and Proportion Questions
• Exercise 2: Direct Proportion Questions
• Exercise 3: Unitary Method Questions
• MCQ Questions on Proportional Reasoning - 1 for Class 8
• Most Repeated Board Questions on Proportional Reasoning - 1 for Class 8
• Frequently Asked Questions on Proportional Reasoning - 1 for Class 8

Exercise 1: Ratio and Proportion Questions

Question 1: Find the ratio of 24 to 36 in simplest form.

Solution

$24:36=2:3$

Answer: 2 : 3

Question 2: Check whether 4, 12, 6, and 18 are in proportion.

Solution

$\frac{4}{12}=\frac{6}{18}=\frac{1}{3}$

Answer: Yes, they are in proportion.

Question 3: Find the fourth proportional to 5, 10, and 20.

Solution

Let the fourth proportional be x.

$\frac{5}{10}=\frac{20}{x}$

$5x=200$

$x=40$

Answer: 40

Question 4: Simplify the ratio 45 : 60.

Solution

$45:60=3:4$

Answer: 3 : 4

Question 5: If the ratio of boys to girls is 7 : 5 and there are 35 boys, find the number of girls.

Solution

$\frac{7}{5}=\frac{35}{x}$

$7x=175$

$x=25$

Answer: 25 girls

Exercise 2: Direct Proportion Questions

Question 1: If 5 notebooks cost ₹100, find the cost of 8 notebooks.

Solution

$\frac{5}{8}=\frac{100}{x}$

$5x=800$

$x=160$

Answer: ₹160

Question 2: A car travels 180 km in 3 hours. How far will it travel in 5 hours at the same speed?

Solution

$\frac{180}{3}=60$

Distance in 5 hours:

$60\times5=300$

Answer: 300 km

Question 3: If 12 pens cost ₹84, find the cost of 20 pens.

Solution

Cost of 1 pen:

$\frac{84}{12}=7$

Cost of 20 pens:

$20\times7=140$

Answer: ₹140

Question 4: A worker earns ₹1500 in 5 days. How much will he earn in 12 days?

Solution

Daily earning:

$\frac{1500}{5}=300$

Earning in 12 days:

$300\times12=3600$

Answer: ₹3600

Question 5: If 8 kg rice costs ₹480, find the cost of 15 kg rice.

Solution

Cost of 1 kg rice:

$\frac{480}{8}=60$

Cost of 15 kg rice:

$15\times60=900$

Answer: ₹900

Exercise 3: Unitary Method Questions

Question 1: If 6 workers can build a wall in 10 days, how much work will 1 worker do in 10 days?

Solution

$\frac{1}{6}\text{ of the wall}$

Answer:$1/6$ of the wall

Question 2: The cost of 9 chocolates is ₹135. Find the cost of 15 chocolates.

Solution

Cost of 1 chocolate:

$\frac{135}{9}=15$

Cost of 15 chocolates:

$15\times15=225$

Answer: ₹225

Question 3: A train travels 240 km in 4 hours. Find the distance travelled in 7 hours.

Solution

Speed per hour:

$\frac{240}{4}=60$

Distance in 7 hours:

$60\times7=420$

Answer: 420 km

Question 4: If 4 books cost ₹320, what is the cost of 9 books?

Solution

Cost of 1 book:

$\frac{320}{4}=80$

Cost of 9 books:

$80\times9=720$

Answer: ₹720

Question 5: A tap fills 150 litres of water in 5 minutes. How much water will it fill in 12 minutes?

Solution

Water filled per minute:

$\frac{150}{5}=30$

Water filled in 12 minutes:

$30\times12=360$

Answer: 360 litres

MCQ Questions on Proportional Reasoning - 1 for Class 8

Question 1: If 3 pens cost ₹45, then 1 pen costs:

A) ₹10
B) ₹12
C) ₹15
D) ₹18

Solution

$\frac{45}{3}=15$

Answer: C) ₹15

Question 2: Which of the following ratios is equivalent to 2 : 5?

A) 4 : 8
B) 6 : 15
C) 8 : 25
D) 10 : 40

Solution

$\frac{6}{15}=\frac{2}{5}$

Answer: B) 6 : 15

Question 3: If 5 kg sugar costs ₹250, then 1 kg sugar costs:

A) ₹40
B) ₹45
C) ₹50
D) ₹55

Solution

$\frac{250}{5}=50$

Answer: C) ₹50

Question 4: The fourth proportional to 3, 6, and 12 is:

A) 18
B) 20
C) 24
D) 30

Solution

$\frac{3}{6}=\frac{12}{x}$

$3x=72$

$x=24$

Answer: C) 24

Question 5: If 8 mangoes cost ₹96, the cost of 1 mango is:

A) ₹10
B) ₹12
C) ₹14
D) ₹16

Solution

$\frac{96}{8}=12$

Answer: B) ₹12

Most Repeated Board Questions on Proportional Reasoning - 1 for Class 8 

Question 1: Find the ratio of 36 to 54 in simplest form.

Solution

$36:54=2:3$

Answer: 2 : 3

Question 2: Check whether 8, 24, 10, and 30 are in proportion.

Solution

$\frac{8}{24}=\frac{10}{30}=\frac{1}{3}$

Answer

Yes, they are in proportion.

Question 3: Find the fourth proportional to 6, 9, and 18.

Solution

Let the fourth proportional be x.

$\frac{6}{9}=\frac{18}{x}$

$6x=162$

$x=27$

Answer: 27

Question 4: If 8 notebooks cost ₹240, find the cost of 15 notebooks.

Solution

Cost of 1 notebook:

$\frac{240}{8}=30$

Cost of 15 notebooks:

$30\times15=450$

Answer: ₹450

Question 5: A car travels 300 km in 5 hours. How far will it travel in 8 hours at the same speed?

Solution

Speed per hour:

$\frac{300}{5}=60$

Distance in 8 hours:

$60\times8=480$

Answer: 480 km

Question 6: If 12 kg wheat costs ₹540, find the cost of 20 kg wheat.

Solution

Cost of 1 kg wheat:

$\frac{540}{12}=45$

Cost of 20 kg wheat:

$45\times20=900$

Answer: ₹900

Question 7: Find the missing term:

$7 : 14 : : 21 : 𝑥$

Solution

$\frac{7}{14}=\frac{21}{x}$

$7x=294$

$x=42$

Answer: 42

Question 8: A worker earns ₹3600 in 12 days. Find his earning in 18 days.

Solution

Daily earning:

$\frac{3600}{12}=300$

Earning in 18 days:

$300\times18=5400$

Answer: ₹5400

Question 9: The ratio of boys to girls in a class is 5 : 6. If there are 30 boys, find the number of girls.

Solution

$\frac{5}{6}=\frac{30}{x}$

$5x=180$

$x=36$

Answer: 36 girls

Question 10: If 15 pens cost ₹225, what is the cost of 24 pens?

Solution

Cost of 1 pen:

$\frac{225}{15}=15$

Cost of 24 pens:

$24\times15=360$

Answer: ₹360

Question 11: Find the ratio of 4 hours to 30 minutes.

Solution

Convert both into minutes.

$4\text{ hours}=240\text{ minutes}$

Ratio:

$240:30=8:1$

Answer: 8 : 1

Question 12: A tap fills 180 litres of water in 6 minutes. How much water will it fill in 15 minutes?

Solution

Water filled per minute:

$\frac{180}{6}=30$

Water filled in 15 minutes:

$30\times15=450$

Answer: 450 litres

Question 13: Find whether the following ratios are equivalent:

$9:12\text{ and }15:20$

Solution

$\frac{9}{12}=\frac{15}{20}=\frac{3}{4}$

Answer: Yes, the ratios are equivalent.

Question 14: If 20 books cost ₹1000, what is the cost of 35 books?

Solution

Cost of 1 book:

$\frac{1000}{20}=50$

Cost of 35 books:

$35\times50=1750$

Answer: ₹1750

Question 15: A train travels 420 km in 7 hours. Find the distance travelled in 10 hours at the same speed.

Solution

Speed per hour:

$\frac{420}{7}=60$

Distance in 10 hours:

$60\times10=600$

Answer: 600 km