2.1. A metal weight has a mass of 20 kg and is an alloy of four metals. The first metal in this alloy is one and a half times more than the second, the mass of the second metal is to the mass of the third as , and the mass of the third to the mass of the fourth - as . Determine the mass of the fourth metal. Give the answer in kilograms, rounding to hundredths if necessary.
Problem 649
Official solution
2.1. A metal weight has a mass of 20 kg and is an alloy of four metals. The first metal in this alloy is one and a half times more than the second, the mass of the second metal is to the mass of the third as , and the mass of the third to the mass of the fourth - as . Determine the mass of the fourth metal. Give the answer in kilograms, rounding to hundredths if necessary.