If set N contains only consecutive positive integers, what is the sum of the numbers in set N?
(1) Nineteen times the sum of the first number in the set and the last number in the set is 1729
(2) There are 38 numbers in the set.
I think i'll go with (C) on this one.
Please allow me to explain.
So they are asking for the sum of the set of consecutive integers. We therefore need 2 things:
1) # of terms = Last - First + 1
2) Average of terms = (First + Last) / 2
Statement 1: We are given that 19 (F+L) = 1729
Then we can find F+L = 91. Hence, we can find the average.
Now can we find Last - First? I'm afraid this is not possible.
Statement 2: We are given the number of terms but we know nothing about the average of the terms. Hence Insuff
(1) and (2): Now we have everything to find the sum of the set. # of terms from Statement 2
Average from Statement 1. Voila
Hence answer is (C)
Kudos if it helps!