A grocery store chain needs to transport of 3000m3 of refrigerated goods and 4000m3 of non-refrigerated goods. They plan to hire truck from a company that has two types of trucks for rent. A truck of type A has a refrigerated goods section of 20m3 and a non-refrigerated goods section of 40m3, while each truck of type B has both sections of the same volume of 30m3. The cost per kilometer of a Type A is $30, and $40 for Type B. How many trucks of each type should the grocer rent to achieve the minimum total cost?
I don't get this.