One reason the railroad company use chinese workers was that they can hire a lot of chinese workers and pay them for a cheap price . The second reason was that there were many of them looking for work .
The railroad company used chinese workers in the west was due to the lack of europeans wishing to do this hard and often hazardous work. Also the cost of chinese workers as opposed to whites was about a third, as the company did not pay for their lodging or food.
The answer is B because they had a highly advanced numeral system with place values. Maya mathematics were also far ahead of Europe for many centuries.
