Hi dferm,

I think the easiest way to do this one is to plug in numbers. Let's say the first month, the whole family earned $100. Thus, Mrs. Lee earned $60, and the rest of the family earned $40.

Now, in the second month, Mrs. Lee earned 20% more, so $72. The rest of the family still earned $40, for a total of $112.

Now we just need to know what 72/112 is as a percent, and with a bit of division we come out to 64%.