the first and the last terms of an AP are 17 and 350 respectively. if the common difference is 9,how many terms are there and what is their sum?
Answers
Answered by
4
Answer:
Total terms :
= 350 = a + ( n-1) d
= 350 = 17 + (n-1)9
= 350 = 17 + 9n - 9
= 350 = 8 + 9n
= 342 = 9n
= n = 38
So, there are 38 terms in the A.P.
Sum :
= 2a + (n-1)d
= 2(17) + 37×9
= 34 + 333
= 267
So, the sum is 267.
Hope it helps you.
Please mark me as brainileast..
Similar questions