Principal \((p) = ₹10,000\) Rate of interest \((r) = 8\%\) Time \((n) = \cfrac{9}{12}\) years \(= \cfrac{3}{4}\) year Interest period \(= \cfrac{3}{12} = \cfrac{1}{4}\) (i.e., quarterly) \(\therefore\) Compound amount for 9 months or \(\cfrac{3}{4}\) year: \[ = 10000\left(1 + \cfrac{\cfrac{8}{4}}{100}\right)^{4 \times \cfrac{3}{4}} = 10000\left(1 + \cfrac{2}{100}\right)^3 = 10000 \times \cfrac{102}{100} \times \cfrac{102}{100} \times \cfrac{102}{100} = ₹10612.08 \] \(\therefore\) Compound interest for 9 months = ₹\(10612.08 - 10000 = 612.08\)