Subject: General Aptitude · Chapter: Ratio and Proportion · Exam: · Marks: · Difficulty:
$A$ and $B$ are two alloys of gold and copper prepared by mixing metals in the ratio 7 : 2 and 7 : 11 respectively. If equal quantities of the alloys are melted to form a third alloy $C$, then the ratio of gold and copper in alloy $C$ will be (M.B.A. 2007; M.A.T., 2005)
(a)5 : 7
(b)5 : 9
(c)7 : 5
(d)9 : 5
Answer
Answer (as printed): C
Explanation
Gold in $C = \left(\frac{7}{9}+\frac{7}{18}\right)$ units $= \frac{7}{6}$ units. Copper in $C = \left(\frac{2}{9}+\frac{11}{18}\right)$ units $= \frac{5}{6}$ units. $\therefore$ Gold : Copper $= \frac{7}{6} : \frac{5}{6} = 7 : 5$.
Explanation as extracted from the printed page; notation may be imperfect.