Data Sufficiency

Hey guys

I'm sure that for the following question, I'm probably blind to the obvious.

If sequence S has 240 terms, what is the 239th terms of S?

(1) Each term of S after the first term is 4 less than the preceding term.
(2) the 239th term of S is 952 less than the first term.

Can anybody help me see the pink elephant in the room?

Many thanks
Lukas

lukaswelker wrote:Hey guys

I'm sure that for the following question, I'm probably blind to the obvious.

If sequence S has 240 terms, what is the 239th terms of S?

(1) Each term of S after the first term is 4 less than the preceding term.
(2) the 239th term of S is 952 less than the first term.

Can anybody help me see the pink elephant in the room?

Many thanks
Lukas

Each statement is only giving info about the common difference ...
I do not see any way in which it provide info about the first term ... according to me answer should be (E) ..
What is the official answer

The answer should be as follows:

For statement 1: As we don't know the starting number of the series, hence we will not be able to find
the 239th sequence in the list even though we know the common difference is 4

For statement 2: Since 239th term is 952 less than the first term, you can't find the first term as you don't know the common difference between any two terms. Also we are not given in this sentence that there is a common difference between any 2 consecutive number in the list.

Combining the first and second sentence, we see that common difference is 4 and 239th term minus 1st term is equal to 952. Using this we still have multiple values for 1st term (960, 956,952) etc. and corresponding 239th term (8, 4, 0) etc. Hence we dont have a single value for 239th term and hence the answer is E

lukaswelker wrote:Hey guys

I'm sure that for the following question, I'm probably blind to the obvious.

If sequence S has 240 terms, what is the 239th terms of S?

(1) Each term of S after the first term is 4 less than the preceding term.
(2) the 239th term of S is 952 less than the first term.

Can anybody help me see the pink elephant in the room?

Many thanks
Lukas

Hi Lukas,

The pink elephant is in your pocket, strange why you cannot feel it.

(1) It suggests that the sequence consists of evenly spaced terms with the regular distinction of -4, but we know no term of the sequence to map it right. Insufficient

(2) 239th term - 1st term = -952, but we don't know the rule how it progresses, insufficient.

Combining, all we know is what we already knew, [spoiler]no fresh gossip.


Hence E[/spoiler]