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Ex 5.3, 2 (i) - Chapter 5 Class 10 Arithmetic Progressions (Term 2)
Last updated at Aug. 3, 2021 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) You are here
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
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 (i) 7 + 101/2 + 14 + ………… + 84 7 + 10 1/2+14+…84 Here, a = 7 d = 10 1/2−7 = 21/2−7 = (21 − 14)/2 = 7/2 Also, last term = 𝒍 = 84 To find sum, first we need to find n Using formula an = a + (n − 1)d Putting a = 7, d = 7/2, an = 84 in the formula 84 = 7 + (n − 1) × 𝟕/𝟐 84 − 7 = (n − 1) × 7/2 77 = (n − 1) × 7/2 77 × 2/7 = (n − 1) 22 = n − 1 n = 22 + 1 n = 23 For sum, we use the formula S = 𝒏/𝟐 (𝒂+𝒍) Putting a = 7, n = 23, l = 84 S = 23/2(7+84) S = 23/2×91 S = 2093/2 S = 1046.5
