dave13 wrote:
snkrhed wrote:
Each • in the mileage table above represents an entry indicating the distance between a pair of the five cities. If the table were extended to represent the distances between all pairs of 30 cities and each distance were to be represented by only one entry, how many entries would the table then have?
(A) 60
(B) 435
(C) 450
(D) 465
(E) 900
(A) 60
(B) 435
(C) 450
(D) 465
(E) 900
Hellogeneris ,
I used this formula to get answer SUM OF N TERMS =\(\frac{n}{2} (2a+(n-1)d)\)
i was almost there but something went wrong
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