How many terms of the A P : -15, -13, -11, are needed - Maths - Arithmetic Progressions

Question

How many terms of the A P : -15, -13, -11, are needed to make the
sum -55? Explain the reason

Varun.Rawat · Accepted Answer

The given AP is–

–15, –13, –11,

Here first term ( a ) = –15 and the common
difference ( d ) = 2

Also given that, sum of n terms = –55

i e S n = –55

Hence sum of 5 terms and 11 terms of the given A P is –55

How many terms of the A.P. : -15, -13, -11, ..... are needed to make the sum -55? Explain the reason.