The volume ratio of oxygen and other gases in the air is 21:79.1320 cubic meters. How many cubic meters of oxygen are there in the air?

The volume ratio of oxygen and other gases in the air is 21:79.1320 cubic meters. How many cubic meters of oxygen are there in the air?

1320 divided by (21 + 79) * 21 = 1320 divided by 100 * 21 = 132 * 21 = 277.2 cubic meters

The volume ratio of oxygen and nitrogen in the air is 21:78.660 cubic meters. How many cubic meters of oxygen and nitrogen are there in the air?

21+78=99,
660 / 99 = 20 / 3
20 * 21 of 3 parts = 420 of 3 parts = 140 cubic meters (oxygen)
20 * 78 of 3 parts = 156 of 3 parts = 520 cubic meters (nitrogen)

The volume ratio of oxygen and nitrogen in the air is 21:78. How many cubic meters of oxygen and nitrogen are there in 660 cubic meters of air?

660 × 2121 + 78 = 660 × 2199 = 140 (cubic meters); 660 × 7821 + 78 = 660 × 7899 = 520 (cubic meters); answer: 660 cubic meters of air contains 140 cubic meters of oxygen and 520 cubic meters of nitrogen