Q6 of 202 Page 9

The first and the last terms of an A.P. are 17 and 350 respectively. If the common difference is 9, how many terms are there and what is their sum?

a = 17, l = 350, d = 9

Number of terms, n = + 1


= + 1


= = = 38


Sn= (a + l)


= (350 + 17)


= 19 (367) = 6973


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