What is the solution to the question?

If the sales price of a dvd is $20 and the markup is 34%, what is the cost of the dvd?

At the "no mutants allowed" country farm, every sheep has 4 legs, every chicken has two legs, and all animals have only 1 head. asked to count how many sheep and chicken are in the fields, a farm boy reports back that there are 140 feet and 50 heads. how many sheep and chicken are there? there are sheep and chicken at the farm.

Solve the following pair of equations for x and y: ax/b_ by /a= a +b; ax - by = 2ab