Three persons A,B,C whose salaries together amount to $144000. Each spend 80,85 & 75 percent of their salaries respectively . If their savings are in the ratio 8:9:20, then C's salary is?
This question came of a very strictly timed test and I was wondering the different ways it can be solved and if there was a faster way to do this?
You can solve quite simply using only basis facts about proportions. Denoting $A, B, C$ the respective salaries, we have this information: $$\frac{0.2A}8=\frac{0.15B}9=\frac{0.25C}{20}\iff \frac A{40}=\frac B{60}=\frac C{80}=\frac{A+B+C}{40+60+80}=\frac{144000}{180}=800$$ whence $C=80\cdot 800=\$\,64000$.