Data Sufficiency

if the terms of a sequence are t1,t2,t3,....,tn, what is the value of n?
1. the sum of the n terms is 3124
2. the average(arithmetic mean) of the n terms is 4

OA C

If the terms of a sequence are t1,t2,t3,....,tn, what is the value of n?
1. the sum of the n terms is 3124
2. the average(arithmetic mean) of the n terms is 4

both together is required to answer the question
because
arthimatic mean = Sum of all the Number/total no odf number(n in this case)

so we as per the data in 1 & 2
arithmetic mean = 4
Sum of all the Number = 3124
hence n= 3124/4 = 781

If the terms of a sequence are t1,t2,t3,....,tn, what is the value of n?

1. the sum of the n terms is 3124

nos of terms may vary depending upon how the terms of the sequence relate to ecah other, eg consecutive series, AP's etc & also the starting value of the sequence INSUFF

2. the average(arithmetic mean) of the n terms is 4

this is also similar to the above case, 4 can be the mean of many possible sequences INSUFF

COMBINE

sum =3124, mean =4

mean =sum /n

n= 3124/4

C

tnx guys i rily appreciate it