Question

The 104th term and 4th term of an A.P. are 125 and 0. Find the sum of first 35 terms​

Answer 1

given a 104= 125

a4=0

now.

to find- S35.

a + 103d=125

a+3d = 0

subtracting we get.

100d =125

d=125/100=5/4

now. d=5/4

a= -15/4..

S35= 35/2(2×-15/4 +34×5/4)

=35/2(-15/2+85/2)

= 35/2×35

=1225/2=612.5

therefore sum of first 35 terms is 612.5

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Answer 2

Hope it will help...