A can finish a job in 12 days. B can finish the same job in 18 days. If they work together, how many days will they take to finish the job?

💡 Find each person's daily rate (1/days), add the rates, then take the reciprocal.

A tap fills a tank in 6 hours. Another tap fills it in 4 hours. If both taps are open together, how long to fill the tank?

💡 Same concept as time & work — each tap's rate is 1/hours.

A alone takes 10 days to do a job. A and B together take 6 days. How many days does B alone take?

💡 Find combined rate first, subtract A's rate to get B's rate, then invert.