Question 462040
.8n+100(.1)=.7(n+100)
.8n+10=.7n+70
.1n=60
n=60/.1=600
You need 600 gallons of 80% antifreeze for your mix.
.8(600)+100(.1)=480+10=490
.7(600+100)=.7(700)=490..