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Ex 5.2, 11 - Chapter 5 Class 10 Arithmetic Progressions
Last updated at April 16, 2024 by Teachoo
Chapter 5 Class 10 Arithmetic Progressions
Concept wise
- Checking if AP or not and finding a, d
- Finding nth term
-
Finding n
- Finding AP
- Finding nth term from end
- Divisible/ multiples
- Statement questions - nth term
- Finding sum of n terms
- Finding number of terms given s
- Given nth term finding s
- Statement questions - Sum of n terms
- Determining AP and finding sum
Transcript
Ex 5.2, 11 Which term of the A.P. 3, 15, 27, 39, … will be 132 more than its 54th term? Given AP 3, 15, 27, 39,… First we need to calculate 54th term Here, a = 3 d = 15 – 3 = 12 n = 54 Putting values in formula a54 = a + (n – 1) d = 3 + (54 – 1) × 12 = 3 + 53 × 12 = 3 + 636 = 639 So, 54th term = a54 = 639 We need to calculate term which is 132 more than 54th term i.e. should be 639 + 132 Therefore, an = 771 We need to find n Putting values in formula an = a + (n – 1) d 771 = 3 + (n – 1) × 12 771 – 3 = (n – 1) × 12 768 = (n – 1) × 12 768/12 = n – 1 64 = n – 1 n – 1 = 64 n = 64 + 1 n = 65 So, 65th term is 132 more than 54th term
