2. A culvert construction project that requires 7 cubic meters of cement, 2 cubic meters of sand and 1½ cubic meters of gravel with a total price of Rp. 850,000, if these materials require additional materials then they need to be procured again with details of 2 cubic meters of cement, 1¼ cubic meters of sand and ¾ cubic meters of gravel. with a total price of IDR 350,000, calculate the price of each material unit (cement, sand and gravel)