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.
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.
x=cost of a ding
y=cost of a bing
z=cost of a ling