Question

How many terms of the series -9,-6,-3..... must be taken so that the sum may be 66

Answer 1

I reached a quadratic that can't be simplified

Answer 2

they all are negative numbers right ?

Answer 3

how can u get a positive sum ?

Answer 4

the series continues , it is in A.P with a common difference "-3"

Answer 5

Oh yes, my brain is 100% dead today :o

Answer 6

loolol happens

Answer 7

so are we trying to solve :

\[\large \dfrac{n}{2}[2(-9) + (n-1)(3)] >= 66\]

?

Answer 8

d = -6-(-9) = -6+9 = 3

Answer 9

oh then i can do it now , i took d as -3

Answer 10

equality will do i think...

Answer 11

So i am getting
n^2 -7n +44 = 0

Answer 12

@ganeshie8

Answer 13

should get

n^2 -7n \(\color{Red}{-}\) 44 = 0

Answer 14

Yeah sry , yes

Answer 15

-11, 4 will do