A alone can do a piece of work in 10 days. B alone can do the same work in 12 days. They work on alternate days starting with A. In how many days will they complete $\frac{3}{4}$ of the total work?
Answer & explanation
Correct answer: option 4
A = 10 days, B = 12 days,
⇒ A + B work on alternate days, starting with A,
1st day = 6 units,
2nd day = 5 units,
Every 2 days, 11 units are done,
So, in 8 days, 44 units are done,
⇒ \(\frac{3}{4}\) of total work = \(\frac{3}{4}\) x 60 = 45 units,
So, in \( { 8}_{6 }^{1 } \) = \(\frac{49}{6}\) days, 45 units of work is completed,