Originally Posted by

**Ash** I'm not sure about solving problems, #1 and #2.

There seems to be different ways to answering these types of problems and the information/question they give varies form problem to problem. Is there a universal setup for these types of problems?

#1

A biologist wishes to have 15 gallons of an 80% formaldehyde solution. In her inventory, she has pure formaldehyde and some 50% formaldehyde solution. How many gallons of each should she mix to obtain the desired solution?

So do I set up the equation 2x+.50(15-x)=15(.80)

so x=3 gallons? ,15-3= 12 gallons