Question 901437
a+b+c=400000,
.13a+.10b+.07c=37600,
c=a+b

a=120000,   b=80000,   c=200000
check
.13a+.10b+.07c=37600
.13(120000)+.10(80000)+.07(200000)=37600
 15600+8000+14000=37600
ok