PS练习题第219
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
答案是D
不知该从何下手,考的知识点是哪里?