Three taps A, B and C can fill a tank in 12, 15 and 20 hours respectively. If A is open all the time and B and C are open for one hour each alternately, the tank will be full in:
Rekha and Sonali received Rs.2800 as wages for 20 days for the work they did together. Rekha’s efficiency in the work was three times that of the Sonali. What are the daily wages of Sonali?