# ratio

• Jan 26th 2010, 01:22 PM
sri340
ratio
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?
• Jan 26th 2010, 01:37 PM
Quote:

Originally Posted by sri340
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?
$3x=5y\ \Rightarrow\ \frac{y}{x}=\frac{3}{5}$
$8y=(5)7z\ \Rightarrow\ \frac{z}{y}=\frac{8}{35}$
$\frac{z}{x}=\frac{z}{y}\ \frac{y}{x}=\frac{8}{35}\ \frac{3}{5}=\frac{24}{175}$