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Ex 5.2, 16 - 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, 16 Determine the A.P. whose third term is 16 and the 7th term exceeds the 5th term by 12 We know that an = a + (n – 1) d Let’s find the 3rd, 5th and 7th term a3 a3 = a + (3 – 1) d 16 = a + 2d a + 2d = 16 a5 a3 = a + (5 – 1)d = a + 4d a7 a7 = a + (7 – 1)d = a + 6d Given that 7th term exceeds the 5th term by 12 7th term – 5th term = 12 a7 – a5 = 12 (a + 6d) – (a + 4d) = 12 a + 6d – a – 4d = 12 a – a + 6d – 4d = 12 0 + 6d – 4d = 12 2d = 12 d = 12/2 d = 6 Putting the value of d in (1) a = 16 – 2d a = 16 – 2 × 6 a = 16 – 12 a = 4 Hence, First term of AP = a = 4 Second term of AP = First term + Common difference = 4 + 6 = 10 Third term of AP = Second term + Common Difference = 10 + 6 = 16 So, the AP is 4, 10, 16, …
