medal will be given! simple 6th grade math! plz help!

Question

amberlykhan · Answer

One part of green pigment mixed with 3 parts of yellow pigment creates lime green.
Suppose the crayon factory is making lime-green crayons. They are going to use 140 total gallons of pigment. How many gallons of yellow and how many gallons of green will be used?

mathmale · Answer

I'd suggest you think of "3 parts of yellow and 1 part of green" as a ratio.
Letting x be the number of gallons of green pigment used and y the number of gallons of yellow, $$\frac{ x }{ y }=\frac{ 1 }{ 3 }.$$
You want 140 gallons total, right?  Then x+y must = 140.  Can you solve this set of simultaneous equations?  Perhaps by using substitution?

amberlykhan · Answer

Yes, thank you.

mathmale · Answer

Good going!  Cool.