Ex 5.3, 2 (iii) - Chapter 5 Class 10 Arithmetic Progressions
Last updated at April 16, 2024 by Teachoo
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 You are here
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
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
Ex 5.3, 16 Important
Ex 5.3, 17
Ex 5.3, 18 Important
Ex 5.3, 19 Important
Ex 5.3, 20 Important
Chapter 5 Class 10 Arithmetic Progressions
Serial order wise
Transcript
Ex 5.3, 2 Find the sums given below (iii) − 5 + (−8) + (−11) + ………… + (−230) − 5 + (−8) + (−11) + ………… + (−230) Here, a = –5 d = –8 – (–5) = –8 + 5 = –3 Also, Last term = 𝒍 = –230 To find sum, first we need to find n Using formula an = a + (n − 1)d Putting a = −5, d = −3, an = −230 in the formula −230 = −5 + (n − 1) × −3 −230 + 5 = (n − 1) × −3 −225 = (n − 1) × −3 (−225)/(−3) = (n − 1) 75 = n − 1 n = 75 + 1 n = 76 For sum, we use the formula S = 𝒏/𝟐 (𝒂+𝒍) Putting a = −5, n = 76, l = −230 Sn = 76/2 (−5 + (−230)) Sn = 38 (– 235) Sn = –8930
