Question: Robyn sends sixteen emails a day. Seven are work emails, and two-thirds of the remainder are to family. One-third of the other emails are to her boyfriend. How many emails a day does she send to her boyfriend?
Answer: 
Robyn sends 16 - 7 = 9 non-work emails.
She sends 9 * 2 / 3 = 6 emails to family.
There are 9 - 6 = 3 emails remaining.
Of the remaining 3, 1/3 are to her boyfriend, so Robyn sends him 3 * 1 / 3 = 1 email a day.