Wa=0.5Wb, Ha=20, Hb is unkown
the area of rectangle a is : Wa*20
the area of rectangle b is : Wb*Hb
Rectangle a has 7 times the area of rectangle b: Wa*20=7*Wb*Hb
Replace Wa with 0.5Wb: 0.5Wb*20=7Wb*Hb => Hb=10/7
Given:
6 male professores
9 female professores
5 male teaching assistants
6 female teaching assistants
Sol:.

N (professors)

N(Male)

N(professors and male)

N(professors OR male) = N(professors) + N(males) -N(professor OR male)

N(People to choose from)

Then probablitiy is:

Then the probability is 10/13
1) I use an interest program on my calculator. You could also use the equation listed in the math textbook. Principle=2500 Rate=0.025 Years=3 No.compounds/yr=4 Answer is $2,694.08
2) All positives
3) Square root of 343
4) Square root of 48
I hope that helps. :)