## 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 Solution 5 Question 6 Solution 6 Question 7 Solution 7 Question 8 Solution 8 Question 9 Solution 9 Question 10 Solution 10 Question 11 Solution 11 Question 12 Solution 12 Question 13 Solution 13 Question 14 Solution 14 Question 15 Solution 15 Question 16 Solution 16 Question 17 Solution 17 Question 18 Solution 18 Question 19 Solution 19 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 Solution 4 Question 5 Solution 5 Question 6 Solution 6 Question 7 Solution 7 Question 8 Solution 8 Question 9 Solution 9 Question 10 Solution 10 Question 11 Solution 11 Question 12 Solution 12 Question 13 Solution 13 Question 14 Solution 14 Question 15 Solution 15 Question 16 Solution 16 Question 17 Solution 17 Question 18 Solution 18 Question 19 Solution 19 Question 20 Solution 20 Question 21 Solution 21 