Hansel

who are the people involved in dark ages?

what are the causes of dark ages?

Two plumbers received a job. At first, one of the plumbers worked alone for 1 hour, and then they worked together for the next 4 hours. After this 40% of the job was finished. How long would it take each plumber to do the whole job by himself if it is kno...

A bus covered the 400-km distance between points A and B at a certain speed. On the way back the bus traveled at the same speed for 2 hours and then increased the speed by 10 km/hour until it reached A, thus spending 20 fewer minutes on the return trip. H...

Two workers, if they were working together, could finish a certain job in 12 days. If one of the workers does the first half of the job and then the other one does the second half, the job will take them 25 days. How long would it take each worker to do t...