Question 187665
x - fast y - slow


"If the ratio of fast workers to slow workers was 9 to 5" ---> x/y=9/5


"there where 2100 workers in all" ---> x+y=2100 ----> y=2100-x



x/y=9/5


x/(2100-x)=9/5


5x=9(2100-x)


5x=18900-9x


5x+9x=18900


14x=18900


x=18900/14


x=1350


Ans #1: 1,350 fast workers


y=2100-x


y=2100-1350


y=750


Ans #2: 750 slow workers