Subject: mathqa
Question: the weight of a glass of jar is 30 % of the weight of the jar filled with coffee beans . after some of the beans have been removed , the weight of the jar and the remaining beans is 60 % of the original total weight . what fraction part of the beans remain in the jar ?
Option: 
A: 3 / 7
B: 1 / 3
C: 1 / 5
D: 2 / 5
Answer: A