I dislike this kind of math, pointless in my eyes
W = 144. Evaluate the equations inside the parentheses. Which is 12 x 12 then evaluate that. Which equals, 144.
Well you have to find out how many cd is 40% and 30%
30% = 30x.3=9
40% = 30x.4=16
now add 16 and 9
16+9=25 now subtract 25 from 30 and see that you have 5 cd of a different type of music to find that as a % divide 5 by 35 to get .14 I rounded it to the nearest hundreth now move the decimal over 2 spots to get 14%