Series question (1 Viewer)

[steve001]

hey.....i know this is a easy question but you have to find the number of terms and the sum = 32, a=2 and d=1.5

 

[gurmies]

I don't think such a sequence exists:

Sn = n/2 (2a + (n-1)d)

32 = n/2 (4 + (n-1)1.5)

64 = n (2.5 + 1.5n)

1.5n^2 + 2.5n - 64 = 0

3n^2 + 5n - 128 = 0

No integral roots to that equation, which is what we are looking for. N has to be a positive integer, as it denotes a term