#### My Profile

1. Inform you about time table of exam.

2. Inform you about new question papers.

3. New video tutorials information.

#### Chapters

1 - Rational Numbers2 - Linear Equations in One Variable

3 - Understanding Quadrilaterals

4 - Practical Geometry

5 - Data Handling

6 - Squares and Square Roots

7 - Cubes and Cube Roots

8 - Comparing Quantities

9 - Algebraic Expressions and Identities

10 - Visualising Solid Shapes

11 - Mensuration

12 - Exponents and Powers

13 - Direct and Inverse Proportions

14 - Factorisation

15 - Introduction to Graphs

16 - Playing with Numbers

#### Where to buy

9 - | ||

190 - |

### Chapter 16 - Playing with Numbers

#### Pages 255 - 256

Find the values of the letters in each of the following and give reasons for the steps involved.

3 A

+ 2 5

-------

B 2

-------

Find the values of the letters in the following and give reasons for the steps involved.

4 A

+ 9 8

------

C B 3

------

Find the value of the letter in the following and give reasons for the steps involved.

1 A

x A

------

9 A

------

Find the values of the letters in the following and give reasons for the steps involved.

A B

+ 3 7

------

6 A

------

Find the values of the letters in the following and give reasons for the steps involved

A B

x 3

-------

C A B

-------

Find the values of the letters in the following and give reasons for the steps involved.

A B

x 5

-------

C A B

-------

Find the values of the letters in the following and give reasons for the steps involved.

A B

x 6

-------

B B B

-------

Find the values of the letters in the following and give reasons for the steps involved.

A 1

+ 1 B

-------

B 0

-------

Find the values of the letters in the following and give reasons for the steps involved.

2 A B

+ A B 1

---------

B 1 8

----------

Find the values of the letters in the following and give reasons for the steps involved.

1 2 A

+ 6 A B

---------

A 0 9

---------

#### Page 260

If 21*y*5 is a multiple of 9, where *y* is a digit, what is the value of *y*?

If 31*z*5 is a multiple of 9, where *z* is a digit, what is the value of *z*? You will find that there are two answers for the last problem. Why is this so?

If 24*x* is a multiple of 3, where *x* is a digit, what is the value of *x*?

(Since 24*x* is a multiple of 3, its sum of digits 6 + *x* is a multiple of 3; so 6 + *x* is one of these numbers: 0, 3, 6, 9, 12, 15, 18…. But since *x* is a digit, it can only be that 6 + *x* = 6 or 9 or 12 or 15. Therefore, *x* = 0 or 3 or 6 or 9. Thus, *x* can have any of four different values)

If 31*z*5 is a multiple of 3, where *z* is a digit, what might be the values of *z*?

#### Where to buy

9 - | ||

190 - |