MCQ
If $a,\;b,\;c$ are in $A.P.$ and $a,\;b,\;d$ in $G.P.$, then $a,\;a - b,\;d - c$ will be in
  • A
    $A.P.$
  • $G.P.$
  • C
    $H.P.$
  • D
    None of these

Answer

Correct option: B.
$G.P.$
b
(b) Given that $a,\;b,\;c$ are in $A.P.$

$ \Rightarrow b = \frac{{a + c}}{2}$…..$(i)$

and ${b^2} = ad$….. $(ii)$

Hence $a,\;a - b,\;d - c$ are in $G.P. $ because

${(a - b)^2} = {a^2} - 2ab + {b^2} = a(a - 2b) + ad$

$ = a(a - a - c) + ad = ad - ac$.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free