大、小兩桶共裝油2.7千克.....比例奧數題（急...）

Let oil in big can = x, then oil in small can=2.7-x.
Oil remaining in big can after giving 1/4 to small can = 3x/4.
Oil in small can becomes( 2.7-x) + x/4.
Therefore, 3x/4 : (2.7 -x + x/4) = 3: 2
That is 3x/4 : (2.7 - 3x/4) = 3: 2,
therefore, 3x/4: (10.8 - 3x)/4 = 3: 2
3x/(10.8 - 3X) = 3/2
6x = 32.4 - 9x
15x = 32.4
therefore, x= 32.4/15=oil in big can, oil in small can = 2.7 - 32.4/15 = 8.1/15.