Swati and Rajni enter into a partnership with their capitals in the ratio 5 : 6. At the end of 7 months Swati withdraws her capital. If they receive the profit in the ratio of 5 : 9, find how long was Rajni's capital used. (I.I.F.T., 2005, R.R.B., 2008)
(a)10 months
(b)12 months
(c)14 months
(d)None of these
Answer
Answer (as printed): D
Explanation
Suppose Swati invested ₹$5x$ for 7 months and Rajni invested ₹$6x$ for $y$ months. Then, $\frac{5x\times7}{6x\times y}=\frac{5}{9} \Rightarrow 30y=315 \Rightarrow y=10\frac{1}{2}$. Hence, Rajni's capital was used for $10\frac{1}{2}$ months.
Explanation as extracted from the printed page; notation may be imperfect.