First slide

Means - A.M/G.M/H.M

Question

$a, b, c, d \in R such that a, b and c are in A.P and b, c and d are in H.P then$

Moderate

A

$a b = c d$
B

$a c = b d$
C

$b c = a d$
D

none of these

Solution

$\begin{array}{l} 2 b = a + c, c = \frac{2 b d}{b + d} \\ \Rightarrow 2 b d = c (b + d) \\ \Rightarrow (a + c) d = c (b + d) [as 2 b = a + c] \\ \Rightarrow a d + c d = b c + c d \\ \Rightarrow b c = a d \end{array}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App