In a AP if the sum of first 16 term is 680
and Common difference 5, find the
first term
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Hey there!
Answer:
S(16) = 680
d = 5
S = n/2{ 2a + (n-1) d}
where n is no of terms
d is common difference
a is first term
680 = 16/2{2a+(16-1)5}
680 = 8 {2a+ 75}
85 = 2a + 75
2a = 10
a = 5
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