A) \[4\frac{2}{3}\]
B) \[7\frac{2}{5}\]
C) \[5\frac{2}{5}\]
D) \[7\frac{1}{7}\]
E) \[5\frac{4}{7}\]
Correct Answer: D
Solution :
A+B= 1624 ?..(i) Again, \[\frac{7A}{12}=\frac{5B}{8}\] \[\Rightarrow \,\,\frac{7A}{3}=\frac{5B}{2}\] \[\Rightarrow \,\,A=\frac{3}{7}\times \frac{5}{2}\,\,\,\,B=\frac{15}{14}\,\,\,B\] \[\therefore \,\frac{15B}{14}+B=1624\] \[\Rightarrow \frac{15B+14B}{14}=1624\] \[\Rightarrow 29B=14\times 1624\] \[\Rightarrow B=\frac{14\times 1624}{29}=784\] \[\therefore A=1624-784=840\] [From equation (i)] \[\therefore \] Required percent \[\left( \frac{840-784}{784} \right)\times 100\] \[=\frac{56}{784}\times 100=\frac{50}{7}=7\frac{1}{7}\]You need to login to perform this action.
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