Bruce and Anne can clean their house in 4 hours working together at their respective constant rates. If Anne’s speed were doubled, they could clean their house in 3 hours working at their respective rates. How many Q hours does it currently take Anne to clean the house on her own? Choose the most appropriate option:
A) 6	B) 7	C) 8	D) 12	E) 14
Lets suppose Anne and Bruce take A and B hrs working separately   So in 1 hour they can together finish 1/A + 1/B portion of the work which equals 1/4 (As the work is completed in 4 hours)   After anne doubles her rate of work the portion completed by the both is 1/A +2/B which is equal to Q=1/3 (As the work is completed in Q=3 hours)   Solving these 2 equations we can find B as 12   So, 12
<result>D</result>
Bruce and Anne can clean their house in 4 hours working together at their respective constant rates. If Anne’s speed were doubled, they could clean their house in 3 hours working at their respective rates. How many Q hours does it currently take Anne to clean the house on her own?