This is a very interesting solution. Readers, wht do you think?
Working with ratios can be confusing. Here is an example: They say that Denny has a 20% solution because his orange juice is 4:1. Why is 4:1 a 20% solution? Draw a picture of what he did, maybe like this:
[juice] [water] [water] [water] [water].
That's 4:1, so that means that one in FIVE is juice. And that's 20%.
But later, they say that a 2:1 solution is 50%. Is that correct? Wouldn't that be
[juice] [water] [water] ?
And that looks to me like 33%...Check with the original problem to see what's up!
Then, see the boldface paragraphs at the bottom? What they say may be correct, or not (I'll never tell!) but it's not obvious to me frrom their explanation why those statements should work.