(X-210+0.2X):(210-0.2X)=3:2
(1.2X-210):(210-0.2X)=3:2
2(1.2X-210)=3(210-0.2X)
2.4x-420=630-0.6x
2.4x+0.6x=630+420
3x=1050
x=350