How many gallons of antifreeze must be mixed with 120 gallons of 20% antifreeze to get a mixture that is 40% antifreeze?

• 40 gallons
  
  The mixture of 120 gallons contains,120*(20/100)=24 gallons of antifreeze
  If 'x' gallons of antifreeze is mixed, to make total 40% antifreez, then
  24+x= (40/100)(120+x), 120+5x=240+2x, x=40
• 10 years agoHelpfull: Yes(0) No(0)