a+b+c+d=940 (1); a+b=440(2) ; d=4c (3);b=2c (4); inlocuim in(1);440+c+4c=940;
5c=940-440=500:5 ,c=100;inloc.in(3), d=4*100=400; inloc.in (4), b=2*100=200;inloc.in(2),a+200=440,a=440-200=240;inloc.in(1), 240+200+c+400=940,c=940-(240+200+400),c=940-840=100; a=240;b=200;c=100,d=400