Two electricians, Harish and Nandini, together wire a house in 8 days. Harish alone would take 12 days. How many days would Nandini take alone?

Explanation

1. 01

   Together they do $\frac{1}{8}$ of the job per day; Harish does $\frac{1}{12}$.

2. 02

   Nandini's rate = $\frac{1}{8} - \frac{1}{12} = \frac{3-2}{24} = \frac{1}{24}$ per day.

3. 03

   So Nandini alone needs 24 days.