A can do a work in 12 days and B can do the same work in 16 days. If they work in it together for 4 days, then the fraction of the work that is left is :
Answer & explanation
Correct answer: option 3
A = 12 days, B = 16 days,
⇒ A + B worked for 4 days = (4 + 3) x 4 = 7 x 4 = 28 units, ..(Efficiency × Days = Total work)
⇒ Fraction of work left = \(\frac{48-28}{48}\) = \(\frac{20}{48}\) = \(\frac{5}{12}\)