The cost of 3 dings is the same as the cost of 5 bings, and 8 bings cost five times

as much as 7 lings. What is the ratio of the cost of a ling to the cost of a ding?

Express your answer as a common fraction.

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- Jan 26th 2010, 01:22 PMsri340ratio
The cost of 3 dings is the same as the cost of 5 bings, and 8 bings cost five times

as much as 7 lings. What is the ratio of the cost of a ling to the cost of a ding?

Express your answer as a common fraction. - Jan 26th 2010, 01:37 PMArchie Meade
x=cost of a ding

y=cost of a bing

z=cost of a ling

$\displaystyle 3x=5y\ \Rightarrow\ \frac{y}{x}=\frac{3}{5}$

$\displaystyle 8y=(5)7z\ \Rightarrow\ \frac{z}{y}=\frac{8}{35}$

$\displaystyle \frac{z}{x}=\frac{z}{y}\ \frac{y}{x}=\frac{8}{35}\ \frac{3}{5}=\frac{24}{175}$