1. If x + y = 13 and 5 x - y = 5, then x - y is equal to   -47   0   -7   7   13   Hint Half-n-half Clue   2. A university has 2000 graduate students. The number of undergraduate students is 4  / 3  times the number of graduate students. What fraction of the students in the university are undergraduates?   3 / 7   4 / 3   7 / 3   4 / 7   7 / 4   Half-n-half Clue   3. Consider a square with side of length a, and an an isosceles right triangle with one side of length a and hypotenuse of length b. What is the sum of the areas of the square and the triangle?   3a2/2   a2 + ab/2   2a2/3   2a3b   a3b/2   Half-n-half Clue   4. There are 520  animals on a farm. Three-fourths of them are cows. Of the cows, about 60% are white. How many cows on the farm are not white?   208   390   130   156   234   Half-n-half Clue