GMATprep
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Given series is an A.P.
for any AP; Tn = T1 + (n-1)d
here d = -3
T1 = 23
& Tn = -4
On solving: n = 10
I believet that this is the fastest solution, however, I am eager to know if there is a still faster approach.
for any AP; Tn = T1 + (n-1)d
here d = -3
T1 = 23
& Tn = -4
On solving: n = 10
I believet that this is the fastest solution, however, I am eager to know if there is a still faster approach.
Thanks Bharat. I was not interpreting it that way. I thought series first increases from t1 to tn and then decreases to t1 and it sum is 23Bharat wrote:Given series is an A.P.
for any AP; Tn = T1 + (n-1)d
here d = -3
T1 = 23
& Tn = -4
On solving: n = 10
I believet that this is the fastest solution, however, I am eager to know if there is a still faster approach.
Not sure how I got the right answer.
This is straigh forward.