7th Maths : Term 2 Unit 3 : Algebra : Exercise 3.2 : Fill in the blanks, Say true or false, Find the value of the following, Objective type questions, Text Book Back Exercises Questions with Answers, Solution

**Exercise
3.2**

**1.
Fill in the blanks.**

(i) Unit digit of 124 × 36 × 980 is __0__.

(ii) When the unit digit of the base
and its expanded form of that number is 9, then the exponent must be ** odd** power.

**2.
Match the following:**

*Answer :*

**i) 20 ^{10 }(c)
0 **

**ii) 121 ^{11 }(d)
1 **

**iii) 444 ^{41 }(b)
4**

**iv) 25 ^{100 }(f)
5 **

**v) 716 ^{83 }(a)
6 **

**vi) 729 ^{725 }(e)
9 **

** **

**3.
Find the unit digit of expanded form.**

**(i)
25 ^{23}**

Unit digit of base 25 is 5 and power is 23 (Odd number).

Thus, the unit digit of 25^{23} is 5.

**(ii)
11 ^{10}**

Unit digit of base 11 is 5 and power is 10 (Even number).

Thus, the unit digit of
11^{10} is 1.

**(iii)
46 ^{15}**

Unit digit of base 46 is 6 and power is 15 (Odd number).

Thus, the unit digit of
46^{15} is 6.

**(iv)100 ^{12}**

Unit digit of base 100 is 0 and power is 12 (Even number).

Thus, the unit digit of 100^{12 }is 0.

**(v)
29 ^{21}**

Unit digit of base 29 is 9 and power is 21 (Odd number).

Thus, the unit digit of 29^{21} is 9.

**(vi)
19 ^{12}**

Unit digit of base 19 is 9 and power is 12 (Even number).

Thus, the unit digit of 19^{12} is 1.

**(vii)
24 ^{25}**

Unit digit of base 24 is 4 and power is 25(Odd number).

Thus, the unit digit of 24^{25} is 4.

**(viii)
34 ^{16}**

Unit digit of base 34 is 4 and power is 16 (Even number).

Thus, the unit digit of 34^{16} is 6.

** **

**4.
Find the unit digit of the following numeric expressions.**

**(i)
114 ^{20} **

Unit digit of base 114 is 4 and power is 20 (Even number).

Thus the unit digit of 114^{20} is 6.

Unit digit of base 115 is 5 and power is 21 (Odd number).

Thus the unit digit of 115^{21} is 5.

Unit digit of base 116 is 6 and power is 22 (Even number).

Thus the unit digit of 116^{22 }is 6.

6 + 5 + 6 = 17

Unit digit of 17 is 7.

So, Unit digit of 114^{20} + 115^{21} +116^{22
}is 7.

**(ii)
10000 ^{10000} **

Unit digit of 10000 is 0 and Power is 10000 (Even number).

So, Unit digit of l0000^{10000}** **is 0.

Unit digit of 11111 is 1 and power is 11111 (Odd number). So, Unit
digit of 11111^{11111} is 1.

** **

__Objective type questions__

**5.
Observe the equation (10 ****+**** y)^{4} **

(i) 1

(ii) 5

(iii) 4

(iv) 0

**Answer: **(ii)
5

**6.
The unit digit of ****(****32 ****×**** 65****)**^{0}** is**

(i) 2

(ii) 5

(iii) 0

(iv) 1

**Answer: **(iv)
1

**7.
The unit digit of the numeric expression 10 ^{71} **

(i) 0

(ii) 3

(iii) 1

(iv) 2

**Answer: **(i)
0

__ANSWERS:__

**Exercise 3.2**

1. (i) 0 (ii) odd

**2. Group A Group B **

(i) : (*c*)

(ii) : (*d*)

(iii) : (*b*)

(iv) : (*f*)

(v) : (*a*)

(vi) : (*e*)

3. (i) 5 (ii) 1 (iii)
6 (iv) 0 (v) 9 (vi) 1 (vii) 4 (viii) 6

4. (i) 7 (ii) 1

**Objective type questions **

5. (ii) 5

6. (iv) 1

7. (i) 0

Tags : Questions with Answers, Solution | Algebra | Term 2 Chapter 3 | 7th Maths , 7th Maths : Term 2 Unit 3 : Algebra

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7th Maths : Term 2 Unit 3 : Algebra : Exercise 3.2 | Questions with Answers, Solution | Algebra | Term 2 Chapter 3 | 7th Maths

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