Class 11

Math

Algebra

Sequences and Series

If $A_{1},A_{2}$ be two arithmetic means between $31 $ and $241 $, then their value are

- $727 ,365 $
- $7217 ,365 $
- $367 ,725 $
- $725 ,7217 $

So the resulting sequence formed an AP

$31 ,P,Q,241 $ are in AP

$∴=241 =31 +(4−1)d$

$→24−7 =3d$

$→d=72−7 $

$∴P=a+d=31 +72−7 $

=$7224−7 $

=$7217 $

and $Q=a+2d=31 +72−14 $

=$7224−14 $

=$365 $