Question

in an AP the first term is 2 and the sum of the first five terms is one fourth of the next five terms find the common difference
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Answer 1

Step-by-step explanation:

first term (a)=2

we know that sum of n terms in AP is

Sn= N/2[2a+(n-1)d]

S5= 5/2[2×2+(5-1)d]

=5/2[4+4d].

sum of next 5 numbers will be

S10-S5

S10=10/2(4+9d)

=5(4+9d).

S10-S5= 5(4+9d)-5/2(4+4d).

by problem

sum of the first five terms=1/4(sum of 5th to 10th terms).

=> 5/2[4+4d]={5(4+9d)-5/2(4+4d).}1/4

=>