If H is the harmonic mean between P and Q, then \(\frac{H}{P}+\frac{H

1.	If H is the harmonic mean between P and Q, then \(\frac{H}{P}+\frac{H}{Q}=\)(a) 2 (b) \(\frac{1}{2}\)(c) \(\frac{PQ}{P+Q}\)(d) \(\frac{P+Q}{PQ}\)
Answer» (a) 2 H being the harmonic mean between P and Q. H = \(\frac{2\,PQ}{P+Q}\) ∴ \(\frac{H}{P}+\frac{H}{Q}=\) \(\frac{2\,Q}{P+Q}\) + \(\frac{2\,Q}{P+Q}\) = \(\frac{2\,(P + Q)}{P+Q}\) = 2.

If H is the harmonic mean between P and Q, then \(\frac{H}{P}+\frac{H}{Q}=\)(a) 2 (b) \(\frac{1}{2}\)(c) \(\frac{PQ}{P+Q}\)(d) \(\frac{P+Q}{PQ}\)

Answer»

(a) 2

H being the harmonic mean between P and Q.

H = \(\frac{2\,PQ}{P+Q}\)

∴ \(\frac{H}{P}+\frac{H}{Q}=\) \(\frac{2\,Q}{P+Q}\) + \(\frac{2\,Q}{P+Q}\) = \(\frac{2\,(P + Q)}{P+Q}\) = 2.