Answer:
4
4
Step-by-step explanation:
x litres of 15% solution + y litres of 19% solution= 8 gallons of 17% solution
disinfectant content of the final solution= 8*0.17= 1.36 gallons
0.15x+0.19y=1.36
x+y= 8 ⇒ x=8-y
- 0.15*(8-y)+0,19y= 1.36
- 1.2-0.15y+0.19y=1.36
- 0.04y=0.16
- y= 0.16/0.04
- y=4 gallons
- x= 8-4= 4 gallons
