Question 902315
0.85*x+0.25*12=0.49(12+x)
0.85*x+3=5.88+0.49x
0.85x-0.49x=5.88-3
0.36x=2.88
x=8 liters at 85% is added to 12 liters of 25% to get  20 liters  at 49%
check
0.85*8+0.25*12=0.49(12+8)
6.8+3=0.49(20)
9.8=9.8
ok