Brew math, figure my gravity after adding H2O

[dickproenneke]

I am BAD at math. I was once laughed right out of 7th grade algebra. No joke. It was terrible.

I need a little help here with some noob brew math.

If I have 5gal wort, with a gravity of 1.055 and I add 0.4gal of H2O, what is my new gravity. What is the formula for this problem?

 

[iaefebs]

Too bad the math in 7th grade didn't involve real world stuff I bet we would have paid more attention. At least you learned H2O

 

[dickproenneke]

File this under duh

(55)(5)/5.4=50.9

My new OG is 1.051