Math, asked by neelshaileshphktnu, 1 year ago

find the sum of first 30 terms of the AP 15,20,25

Answers

Answered by RAJPUTANALIONS
7

15.20.25.30.35.40.........are \: in \: ap \\ here \: a = 15 \: d = 5 \\ then \: sn \:  =  \frac{n}{2}{({2a + nd - d})} \\  \frac{30}{2} (2 \times15 + 30 \times 5 - 5) \\ 15(30 + 150 - 5) \\ 15(175) \\ 2625
Answered by Anonymous
13

Just use this formula to find the sum:-

S=\frac{n}{2}*[2a+(n-1)d]

\implies \frac{30}{2}*[2*15+(30-1)5]

\implies 15*[30+145]

\implies 15*175

\implies 2625

Thats the answer mate:2625

Hope it helps.

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