First one - Because it says 2 years ago, you can do 60000-4% for one year and then take the answer and - another 4% for the second year to get her income from 2 years ago. (I commented on this)
Second one - 1/3 - Take 1/6*200%=1/6*2=2/6, 2/6=1/3. So 1/3 or 2/6 of the students have a engineering major
