KCET2023MathematicsSequences and Series
If p ( 1 q + 1 r ), q ( 1 r + 1 p ), r ( 1 p + 1 q ) are in AP , then p, q, r
Options
- Aare in GP
- Bare in AP
- Care not in GP
- Dare not in AP
Correct answer
B. are in AP
Step-by-step solution
p ( 1 q + 1 r ) q ( 1 r + 1 p ) r ( 1 p + 1 q ) aligned & =p ( q+r q r ), q ( p+r p r ), r ( p+q p q ) & = p(q+r) q r +1, q(p+r) p r +1, r ( p+q p q )+1 aligned (On adding l each term) = p q+p r+q r q r , q p+q r+p r p r , r p+r q+p q p q aligned & = 1 q r , 1 p r , 1 p q in AP & = p q r q r , p q r p r , p q r p q in APs aligned (on multiply pqr both order) p, q, r also in AP.