Bunuel wrote:
Is the sum of all the terms in a sequence of positive integers an odd integer?
(1) The sequence is composed of consecutive integers.
(2) There are 50 terms in the sequence.
DS21280
(1) We don't know how many integers are in the set.
We could have 1 odd integer in the set, which would give us an odd sum.
We could have 1 even integer in the set, which would give us an even sum.
INSUFFICIENT.
(2) If there are 50 terms in the sequence, we could have 50 2's, which could give us a sum of 100.
We could have 49 1's and one 2, which would give us an odd sum (101)
INSUFFICIENT.
(1&2) If we have 50 consecutive integers, we will have 25 even integers and 25 odd integers.
Sum of 25 even integers = even
Sum of 25 odd integers = odd
even + odd = odd
SUFFICIENT.
Answer is C.
_________________
Help me get better -- please critique my responses!