A rectangular storage container with an open top is to have a volume of 10 m 3 . The length of this base is twice the width. Material for the base costs $15 per square meter. Material for the sides...

A rectangular storage container with an open top is to have a volume of 10 m³. The length of this base is twice the width. Material for the base costs $15 per square meter. Material for the sides costs $9 per square meter. Find the cost of materials for the cheapest such container.