Question

Mark the correct alternative in the following question:

If 2x = 3y and 4y = 5z, then x : z =

(a) 4 : 3 (b) 8 : 15 (c) 3 : 4 (d) 15 : 8

Answer 1

$$\begin{gathered} \mathrm{As},2x=3y \\ \Rightarrow \frac{x}{y}=\frac{3}{2} \\ \mathrm{And},4y=5z \\ \Rightarrow \frac{y}{z}=\frac{5}{4} \\ \mathrm{Now},x:z=\frac{x}{z} \\ =\frac{xy}{yz} \\ =\frac{x}{y}\times \frac{y}{z} \\ =\frac{3}{2}\times \frac{5}{4} \\ =\frac{15}{8} \\ =15:8 \end{gathered}$$

Hence, the correct alternative is option (d).