Q. If a:b=5:7, find (3a+5b):(5a-2b)
Answer: 50:11
Notes: $latex \because \frac{a}{b}=\frac{5}{7}&S=2$ $latex \therefore \frac{\left ( 3a+5b \right )}{5a-2b}=\frac{3\left ( \frac{a}{b} \right )+5}{5\left ( \frac{a}{b} \right )-2}&S=2$ $latex =>\frac{3\times \frac{5}{7}+5}{5\times \frac{5}{7}-2}=\frac{50}{11}&S=2$ $latex =>a:b=50:11 $ Hence option [C] is the right answer.

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