A can do a work in 15 days and B can do it in 10 days. If they work together for 4 days, then the fraction of the work that is left is:
Answer & explanation
Correct answer: option 3
A = 15 days, B = 10 days,
⇒ A + B worked for 4 days = (2 + 3) x 4 = 5 x 4 = 20 units,
⇒ Remaining work = 30 - 20 = 10 units,
⇒ Fraction of work left = \(\frac{10}{30}\) = \(\frac{1}{3}\)