Hello, classmate. This problem is above average in the mathematics of the joint entrance examination for master of management. Although it is easy to understand in principle, you still need to master some skills in the actual process. The answer is as follows:

Assume that the number of first prize, second prize and third prize is X, Y, Z, Y and Z respectively. According to the meaning of the question, there are 1.5x+y+0.5z= 100. For the condition of 1, the following counterexamples can be given: x=33, y=50, z= 1, then obviously the conclusion that the number of people is less than 100 cannot be drawn.

For condition 2, we can know that there is 200 = 3x+2y+z = (x+y+z)+(y+z+z) ≤ 2 (x+y+z), so the number of people is greater than or equal to 100, so condition 2 is sufficient. So the answer is B. For more detailed MBA questions, you can also check out "Analysis of Mathematics True Questions over the Years" and "The Book of Mathematics High Score Breakthrough" published by Mr. Peng in Shanghai Jiaotong University.