Subject: mathqa
Question: a , b and c start a business each investing 20,000 . after 10 months a withdrew 5000 , b withdrew 4000 and c invests 6000 more . at the end of the year , a total profit of 71400 was recorded . find the share of b .
Option: 
A: 20,000
B: 20,500
C: 23,200
D: none of these
Answer: C