217. In a certain game, a large container is filled with red, yellow, green, and blue beads worth, respectively, 7, 5, 3, and 2 points each. A number of beads are then removed from the container. If the product of the point values of the removed beads is 147,000, how many red beads were removed? (A) 5 (B) 4 (C) 3 (D) 2 (E) 0 Arithmetic Properties of numbers From this, the red beads represent factors of 7 in the total point value of 147,000. Since 147,000 = 147(1,000), and 1,000 = 10 3, then 147 is all that needs to be factored to determine the factors of 7. Factoring 147 yields 147 = (3)(49) = (3)(72). Th is means there are 2 factors of 7, or 2 red beads. Th e correct answer is D. 看了解释还是不明白，有没有人解释一下？
