A can do 50 more work than B in the same time B alone can do a piece of work in 30 hours B starts wo...........

Quantitative Aptitude (CDS) Time and work

A can do 50% more work than B in the same time. B alone can do a piece of work in 30 hours. B starts working and had already worked for 12 hours when A joins him. How many hours should B and A work together to complete the remaining work?

6 hours