If x : y = 7 : 3, then the value of $$\frac{{xy + {y^2}}}{{{x^2} - {y^2}}}$$ is
A. $$\frac{3}{4}$$
B. $$\frac{4}{3}$$
C. $$\frac{3}{7}$$
D. $$\frac{7}{3}$$
Answer: Option A
Solution(By Examveda Team)
$$\eqalign{ & = \frac{x}{y} = \frac{7}{3} \cr & = \frac{{xy + {y^2}}}{{{x^2} - {y^2}}} \cr & = \frac{{\left( {\frac{x}{y}} \right) + 1}}{{\left( {\frac{{{x^2}}}{{{y^2}}}} \right) - 1}} \cr & = \frac{{\frac{7}{3} + 1}}{{{{\left( {\frac{7}{3}} \right)}^2} - 1}} \cr & = \frac{{10}}{3} \times \frac{9}{{40}} \cr & = \frac{3}{4} \cr} $$Related Questions on Ratio
If a : b : c = 3 : 4 : 7, then the ratio (a + b + c) : c is equal to
A. 2 : 1
B. 14 : 3
C. 7 : 2
D. 1 : 2
If $$\frac{2}{3}$$ of A=75% of B = 0.6 of C, then A : B : C is
A. 2 : 3 : 3
B. 3 : 4 : 5
C. 4 : 5 : 6
D. 9 : 8 : 10
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