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3 years ago

The given series has six terms. what is the sum of the terms of the series? 10 + 25 + 40 + . . . + 85

Mathematics

2 answers:

tatiyna3 years ago

4 0

10+25+40+55+70+85
35+95+155
130+155
285

answer: 285

cupoosta [38]3 years ago

4 0

Answer with Step-by-step explanation:

The sum of first n terms of an arithmetic progression is given by:

$S(n)=\dfrac{n}{2}\times (A1+An)$

10+25+40+...+85

Since, the terms have a common difference of 15

So, it is an arithmetic progression of n=6 terms with first term A1=10

and A6=85

We have to find S(6)

$S(6)=\dfrac{6}{2}\times (10+85)$

= 285

Hence, the sum of the terms of the series 10 + 25 + 40 + . . . + 85 is:

285

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Step-by-step explanation:

We assume that th data is this one:

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