College Algebra & Trigonometry, 2018a

84 CHAPTER 1. ALGEBRA REVIEW
26) One military horse and one ordinary horse can pull a load of 40 dan. Two
ordinary horses and one inferior horse can pull the same load of 40 dan as can
three inferior horses and one military horse. How much can each horse pull individually?
(Ancient China)
27) A barrel of water has several holes in it. The first hole empties the full barrel
in 3 days. The second hole empties the full barrel in 5 days. The third hole
empties the full barrel in 20 hours and the last hole empties the full barrel in 12
hours. With all the holes open, how long will it take to empty the barrel?
(Levi ben Gershon, French 1321)
28) A certain lion could eat a sheep in 4 hours; a leopard could do so in 5 hours;
and a bear in 6 hours. How many hours would it take for all three animals to devour
a sheep if it were thrown in among them? (Fibonacci, Italian 1202)
29) Two ships are some distance apart, which journey the first can complete in
5 days and the other in 7 days - it is sought in how many days they will meet if
they begin the journey at the same time. (Fibonacci, Italian 1202)
30) Sarah, alone, can paint the garage in 24 hours, her sister Jenny, alone, can
paint the same garage in 12 hours. With the aid of their mother, the three together
can paint the garage in 4 hours. How long would it take their mother, working
alone, to paint the garage?
31) It required 75 workers 38 days to build an embankment to be used for flood
control. Had 18 workers been removed to another job at the very start of operations,
how much longer would it have taken to build the embankment?
32) Mark, alone, requires 6 hours to paint a fence; however, his younger brother,
who alone could do it in 9 hours, helps him. If they start work at 8:30am, at what
time should they finish the work?