Students can Download Maths Chapter 4 Direct and Inverse Proportion Intext Questions and Answers, Notes Pdf, Samacheer Kalvi 7th Maths Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.
Tamilnadu Samacheer Kalvi 7th Maths Solutions Term 1 Chapter 4 Direct and Inverse Proportion Intext Questions
Try These (Text Book Page No. 72)
Question 1.
Find the ratio of the number of circles to number of squares.
Solution:
Number of circles = 4 ;
Number of squares = 6
Number of circles : Number of squares = 4 : 6 = 2 : 3
Question 2.
Find the ratio (i) 555 g to 5 kg
(ii) 21 km to 175 m.
Solution:
(i) 1 kg = 1000 g
∴ 5 kg = 5000 g
∴ 555 g : 5 kg = 555 g : 5000 g = 111 : 1000
(ii) 21 km to 175m
1 km = 1000 m
21 km = 21 × 1000 = 21,000m
∴ 21 km : 175 m = 21000 : 175 = 120 : 1
Question 3.
Find the value of x in the following proportions :
(i) 110 8: 88
(ii) x : 26 :: 5: 65
Solution:
(i) Given 110 : x :: 8 : 88
Product of the means = Product of the extremes
x × 8 = 110 × 88
(ii) x : 26 :: 5 : 65
Product of the means = Product of the extremes
Try this (Text Book Page No. 74)
Question 1.
The number of chocolates to be distributed to the number of children. Is this statement in direct proportion?
Solution:
Let the number of students be x and the number of chocolates be y. As the valve of x increases also correspondingly increases.
ie \(\frac{x}{y}=k\)
∴ x and y are in direct proportion.
Try This (Text book Page No. 74)
Question 2.
Observe the following 5 squares of different sides given in the graph sheet.
The measures of the sides are recorded in the table given below. Find the corresponding perimeter and the ratios of each of these with the sides given and complete the table.
From the information so obtained state whether the side of a square is in direct proportion to the perimeter of the square.
Solution:
Perimeter of the square y = 4x, units where x is the side of a square
Completing the table
From the above table we find that as x increases y also increased in such a way that \(\frac{x}{y}=\frac{1}{4}\), constant.
∴ Side of a square is in direct proportion to the perimeter of the square.
Try this (Text book Page No. 75)
Question 3.
When a fixed amount is deposited for a fixed rate of interest, the simple interest changes proportionally with the number of years it is being deposited. Can you find any other examples of such kind.
Solution:
Some other examples of such kind are
(i) Cost of book and number of books
(ii) Distance and time to travel
(iii) Men workers and wages.
Exercise 4.2
Try this (Text book Page No. 78)
Question 1.
Think of an example in real life where two variable are inversely proportional.
Solution:
Example of inverse proportion are
(i) Men working and the amount of work.
(ii) Speed and time to travel
Try These (Text book Page No. 78)
Question 1.
Complete the table given below and find the type of proportion.
Solution:
Question 2.
Read the following examples and group them in two categories.
Solution: