Fill in the blanks in the following table, given that a is the first term, d the common difference and aₙ the n^th term of the AP:

a	d	n	aₙ
7	3	8	…….
- 18	……..	10	0
…….	-3	18	-5
-18. 9	2.5	…….	3.6
3.5	0	105	…….

Solution:

The formula for the n^th term of an AP is, aₙ = a + (n - 1)d.

i) Given: a = 7, d = 3, n = 8

aₙ = a + (n - 1)d

a₈ = 7 + (8 - 1)3

= 7 + 7 × 3

= 7 + 21

= 28

aₙ = 28

ii) Given: a = -18, aₙ = 0, n = 10

aₙ = a + (n - 1)d

0 = - 18 + (10 - 1)d

0 = - 18 + 9d

9d = 18

d = 2

d = 2

iii) Given: d = -3, aₙ = - 5, n = 18

- 5 = a + (18 - 1)(- 3)

- 5 = a + 17 × (- 3)

a = 46

iv) Given: aₙ = 3.6, d = 2.5, a = - 18.9

aₙ = a + (n - 1)d

3.6 = - 18.9 + (n - 1) 2.5

3.6 + 18.9 = 2.5 (n - 1)

22.5 = 2.5 (n - 1)

n - 1 = 22.5 / 2.5

n - 1 = 9

n = 10

v) Given: a = 3.5, d = 0, n = 105

aₙ = a + (n - 1)d

aₙ = 3.5 + (105 - 1) (0)

aₙ = 3.5 + 104 × 0

aₙ = 3.5

a	d	n	aₙ
7	3	8	28
- 18	2	10	0
46	-3	18	-5
-18. 9	2.5	10	3.6
3.5	0	105	3.5

☛ Check: NCERT Solutions for Class 10 Maths Chapter 5

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Video Solution:

Fill in the blanks in the following table, given that a is the first term, d the common difference and aₙ the n^th term of the AP:

a	d	n	aₙ
7	3	8	…….
- 18	……..	10	0
…….	-3	18	-5
-18. 9	2.5	…….	3.6
3.5	0	105	…….

NCERT Solutions Class 10 Maths Chapter 5 Exercise 5.2 Question 1

Summary:

The blanks in the following table is filled above, given that a is the first term, d the common difference and aₙ the n^th term of the AP: i) aₙ = 28, ii) d = 2, iii) a = 46, iv) n = 10 and v) aₙ = 3.5 respectively

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☛ Related Questions:

• Choose the correct choice in the following and justify:i) 30th term of the AP: 10, 7, 4……. isa) 97 b) 77 c) - 77 d) - 87ii) 11th term of AP: -3, - 1/2, 2 is:a) 28 b) 22 c) - 38 d) - 48 (1/2)
• In the following AP, find the missing terms in the boxes: i) 2, _, 26 ii) _, 13, _ , 3 iii) 5, _ , _ , 9 ½ iv) - 4, _ , _ , _ , _ , 6 v) _ , 38, _ , _ , _ , - 22.
• Which term of the AP: 3, 8, 13, 18……. is 78.
• Find the number of terms in each of the following APs: i) 7, 13, 19,..., 205 ii) 18, 15 ½, 13 ,..., - 47.