Q23 of 102 Page 410

The sum of first 7 terms of an AP is 10 and that of next 7 terms is 17. Find the AP.

To Find: AP


Given: Sum of first 7 terms = 10
Sum of next 7 terms = 17


According to the problem,


Sum of first 14 terms of the given AP is 10 + 17 = 27.


So we can say


Solving the equations we get 14a + 42d = 20…(i) and


14a + 91d = 27… (


subtracting (i)from (ii)we get 49d = 7




⇒a = 1



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