The sum of the 5th and 9th terms of an A.P is 40 and the sum of the 8th and 14th term is 64. Find the sum of first 20 terms.
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Answer:
Sum of 20 terms of the given AP is 610
Step-by-step explanation:
Points to Remember:
- In an AP the general term =a+(n-1)d
- here a is the first term
- n is the number of terms
- d is the common difference
- sum of n terms in the AP is =n/2[2a+(n-1)d]
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