FRANK Solutions for Class 9 Maths Chapter 6 - Changing the subject of a formula

Chapter 6 - Framing of Formulae Exercise Ex. 6.1

Question 1

The simple interest on a sum of money is the product of the sum of money, the number of years and the rate percentage. Write the formula to find the simple interest on Rs A for T years at R% per annum.

Solution 1

Question 2

Solution 2

Question 3

The fahrenheit temperature, F is 32 more than nine -fifths of the centigrade temperature C. Express this relation by a formula.

Solution 3

Question 4

The arithmetic mean M of the five numbers a, b, c, d, e is equal to their sum divided by the number of quantities. Express it as a formula.

Solution 4

Question 5

Make a formula for the statement :"The reciprocal of focal length f is equal to the sum of reciprocals of the object distance u and the image distance v."

Solution 5

Question 6

Make a formula for the statement:"The number of diagonals, d, that can be drawn from one vertex of an n sided polygon to all the other vertices is equal to the number of sides of the polygon less 3"

Solution 6

Question 7

Solution 7

Question 8

A man bought 25a articles at 30p paisa each and sold them at 20q paisa each. Find his profit in rupees.

Solution 8

Question 9

How many minutes are there in x hours, y minutes and z seconds.

Solution 9

Question 10

Apple cost x rupees per dozen and mangoes cost y rupees per score. Write a formula to find the total cost C in rupees of 20 apples and 30 mangoes.

Solution 10

Chapter 6 - Changing the subject of a formula Exercise Ex. 6.2

Question 1

Given: mx + ny = p and y = ax + b. Find x in terms of m, n, p, a and b.

Solution 1

Question 2

If A =  pr² and C = 2pr, then express r in terms of A and C.

Solution 2

Question 3

If V = pr²h and S = 2pr² + 2prh, then express V in terms of S, p and r.

Solution 3

Question 4

If 3ax + 2b² = 3bx + 2a², then express x in terms of a and b. Also, express the result in the simplest form.

Solution 4

Question 5

 

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Question 6

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Question 7

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Question 8

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Question 9

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Question 10

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Question 11

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Question 12

Solution 12

Question 13

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Question 14

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Question 15

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Question 16

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Question 17

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Question 18

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Question 19

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Question 20

Solution 20

Chapter 6 - Changing the subject of a formula Exercise Ex. 6.3

Question 1

The pressure P and volume V of a gas are connected by the formula PV = C; where C is a constant.

 

Solution 1

Question 2

The total energy E possess by a body of Mass 'm', moving with a velocity 'v' at a height 'h' is given by:

Make 'm' the subject of formula.

Solution 2

Question 3

The total energy E possess by a body of Mass 'm', moving with a velocity 'v' at a height 'h' is given by:

Find m, if v = 2, g = 10, h = 5 and E = 104.

Solution 3

Question 4

 

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Question 5

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Question 6

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Question 7

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Question 8

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Question 9

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Question 10

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Question 11

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Question 12

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Question 13

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Question 14

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Question 15

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Question 16

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Question 17

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Question 18

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Question 19

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Question 20

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Question 21

Solution 21