The average of the first five prime numbers is:

   (A) 3:5      (B) 2:5      (C) 5:3      (D) None of these  

Explanation To factorize the expression y^2 + y – 6, we need to find two numbers whose product is -6 and whose sum is 1 (the coefficient of the middle term). These numbers are 3 and -2, so we can write: y^2 + y – 6 = (y + 3)(y – 2)

(A) 472.88      (B) 495.22      (C) 500.88    (D) None of these