**GSEB Solutions for Class 9 Mathematics – Number System (English Medium)**

GSEB SolutionsMathsScience

**Exercise 2:**

**Solution 1:**

**Solution 2:**

**Solution 3:**

**Solution 4:**

**Solution 5:**

**Solution 6(1):**

**Solution 6(2):**

**Solution 6(3):**

**Solution 6(4):**

**Solution 7:**

**Solution 8:**

**Solution 9:**

**Solution 10:**

**Solution 11:**

**Solution 12:**

**Solution 13:**

**Solution 14:**

**Solution 15:**

**Solution 16:**

**Solution 17:**

**Solution 18(1):**

a. N

Set of all natural numbers is denoted by N.

**Solution 18(2):**

b. W

Set of all whole numbers is denoted by W.

**Solution 18(3):**

c. Z

Set of all integers is denoted by Z.

**Solution 18(4):**

d. Q

Set of all rational numbers is denoted by Q.

**Solution 18(5):**

b. Every integer is a rational number

N = Natural Numbers

W = Whole Numbers

Z = Integers

Q = Rational numbers

R = Real Numbers

N ⊂ W ⊂ Z ⊂ Q ⊂ R

**Solution 18(6):**

**Solution 18(7):**

**Solution 18(8):**

**Solution 18(9):**

**Solution 18(10):**

d. infinitely many

There are __infinitely many__ rational numbers between two given numbers.

**Solution 18(11):**

**Solution 18(12):**

b. the set of real numbers

The collection of rational numbers and irrational numbers together is called the set of real numbers.

**Solution 18(13):**

**Solution 18(14):**

**Solution 18(15):**

**Solution 18(16):**

d. a rational number

0.235 is a terminating decimal.

∴ The number 0.235 is a rational number.

**Solution 18(17):**

**Solution 18(18):**

**Solution 18(19):**

**Solution 18(20):**

**Solution 18(21):**

**Solution 18(22):**

**Solution 18(23):**

**Solution 18(24):**

**Solution 18(25):**

**Solution 18(26):**

**Solution 18(27):**

**Solution 18(28):**

**Solution 18(29):**

**Solution 18(30):**

**Solution 18(31):**

**Solution 18(32):**

**Solution 18(33):**

**Solution 18(34):**

**Solution 18(35):**

**Solution 18(36):**

**Exercise 2.1:**

**Solution 1:**

**Solution 2:**

**Solution 3:**

**Solution 4:**

**Solution 5:**

**Exercise 2.2:**

**Solution 1:**

**Solution 2:**

On the number line m, take point O corresponding to zero.

Now take point P on line m such that OP = 2 unit.

Construct right angled Δ OPA such that m∠OPA = 90° and PA = 1 unit.

**Solution 3:**

On the number line m, take point O corresponding to zero. Take point P on line m such that OP = 4 units.

Construct right angled ΔOPA such that mOPA = 90° and PA = 1 unit.

**Exercise 2.3:**

**Solution 1:**

**Solution 2(1):**

**Solution 2(2):**

**Solution 2(3):**

**Solution 2(4):**

**Solution 2(5):**

**Solution 2(6):**

**Solution 3:**

**Solution 4:**

**Solution 5(1):**

**Solution 5(2):**

**Solution 5(3):**

**Solution 6:**

**Exercise 2.4:**

**Solution 1(1):**

**Solution 1(2):**

**Solution 1(3):**

**Solution 1(4):**

**Solution 1(5):**

**Solution 1(6):**

**Solution 2(1):**

**Solution 2(2):**

**Solution 2(3):**

**Solution 2(4):**

**Solution 2(5):**

**Solution 2(6):**

**Solution 3:**

**Solution 4(1):**

**Solution 4(2):**

**Solution 4(3):**

**Solution 4(4):**

**Solution 4(5):**

**Solution 5(1):**

**Solution 5(2):**

**Solution 5(3):**

**Solution 5(4):**

**Solution 5(5):**

**Exercise 2.5:**

**Solution 1:**

**Solution 2:**

**Solution 3:**