LP Linear Programming use solver excel

Your company received a highway bridge construction project from Beautiful city that will connect the kingdom of Falmuth with Beautiful city's Jura Forest. The composition of the materials to build the bridge are stone, sand and cement. All of these materials can be purchased in Kg units. Every Kg of stone used will strengthen the bridge and can withstand a load of 10Kg/ meter but makes it difficult to make concrete by 10 points, but the mixture requires at least 10% stone of the concrete mix. Every kg of sand used does not strengthen the bridge, but helps make concrete by 20 points. Cement is used as an adhesive or glue that strengthens the strength of concrete by 5kg/meter and makes concrete easier by 5 points. The concrete composition must contain a minimum of 20% cement and a maximum of 50% cement. In every one meter of the bridge, a minimum of 120kg of concrete is required which is a mixture of stone, sand and cement. The cost per 1Kg of stone is IDR 30,000 ; Sand IDR 15,000 and Cement IDR 20,000 . Concrete strength must be able to withstand a pressure of at least 1 ton/meter to be suitable for use. Workability or manufacture of concrete must have a score of at least 800 points. If it is below that, the concrete becomes difficult to mix. The budget provided by Beautiful city is IDR 3,500,000 per meter. How do you, as the project owner, run the project to get the maximum profit