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Ex 5.3, 4 How many terms of the AP. 9, 17, 25 β¦ must be taken to give a sum of 636? Given AP is 9, 17, 25, β¦.. Here, a = 9 d = 17 β 9 = 8 & Sum = Sn = 636 We need to find n We know that Sum = π/2 (2a + (n β 1) d) Putting a = 9, d = 8, Sn = 636 636 = π/(2 ) (2 Γ 9 + (n β 1) Γ 8) 636 Γ 2 = n (18 + 8n β 8) 1272 = n (10 + 8n) 1272 = 10n + 8n2 0 = 10n + 8n2 β 1272 10n + 8n2 β 1272 = 0 2(5n + 4n2 β 636)= 0 5n + 4n2 β 636 = 0 4n2 + 5n β 636 = 0 We solve by quadratic formula Comparing equation with ax2 + bx + c = 0 Here, a = 4, b = 5, c = β 636 We know that, D = b2 β 4ac D = (5)2 β 4 Γ 4 Γ (β636) D = 25 + 10176 D = 10201 Hence, roots to equation are given by n = (β π Β± βπ«)/ππ Putting values n = (β 5 Β± βπππππ)/(2 Γ 4) n = (β π Β± πππ)/π Finding root of 10201 10201 = 101 Γ 101 10201 = 1012 So, β("10201" ) = 101 Solving So, n = 12 & n = (β53)/4 Since n cannot be negative, β΄ n = 12 n = (βπ + πππ)/π n = 96/8 n = 12 n = (βπ β πππ)/π n = (β106)/8 n = (βππ)/π

Ex 5.3

Ex 5.3, 1 (i)

Ex 5.3, 1 (ii)

Ex 5.3, 1 (iii) Important

Ex 5.3, 1 (iv)

Ex 5.3, 2 (i)

Ex 5.3, 2 (ii)

Ex 5.3, 2 (iii) Important

Ex 5.3, 3 (i)

Ex 5.3, 3 (ii)

Ex 5.3, 3 (iii)

Ex 5.3, 3 (iv) Important

Ex 5.3, 3 (v)

Ex 5.3, 3 (vi) Important

Ex 5.3, 3 (vii)

Ex 5.3, 3 (viii) Important

Ex 5.3, 3 (ix)

Ex 5.3, 3 (x)

Ex 5.3, 4 You are here

Ex 5.3, 5

Ex 5.3, 6 Important

Ex 5.3, 7

Ex 5.3, 8

Ex 5.3, 9

Ex 5.3, 10 (i)

Ex 5.3, 10 (ii) Important

Ex 5.3, 11 Important

Ex 5.3, 12

Ex 5.3, 13

Ex 5.3, 14 Important

Ex 5.3, 15 Deleted for CBSE Board 2022 Exams

Ex 5.3, 16 Important Deleted for CBSE Board 2022 Exams

Ex 5.3, 17 Deleted for CBSE Board 2022 Exams

Ex 5.3, 18 Important Deleted for CBSE Board 2022 Exams

Ex 5.3, 19 Important Deleted for CBSE Board 2022 Exams

Ex 5.3, 20 Important Deleted for CBSE Board 2022 Exams

Chapter 5 Class 10 Arithmetic Progressions (Term 2)

Serial order wise

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.