over the last three years, sales person A has earned twice as much as Salesperson B, who

Equations: A=2B, B=0.5C+C. You can also say A=2(0.5C+C), A=C+2C, A=3C

Now, we have A+B+C=$220

Plugging in the values, we have 3C+0.5C+C+C=220

5C+0.5C=220

5.5C=220

C=40

And, B= 0.5(40)+40=20+40=\(\boxed{60}\).

Or, is that a comma after that 220?

Let the sales of Person C = S

The sales of Person B      =1.5S

The sales of Person A      =2 x 1.5S =3S

S + 1.5S + 3S =$220,000

5.5S = $220,000

S =$220,000 / 5.5

S =$40,000 - total earning of salesperson C over a 3-year period.

$40,000 x 1.5 =$60,000 - total earning of salesperson B over a 3-year period.

$60,000 / 3 =$20,000 - average earning of salesperson B per year for 3 years.

Edited: Sorry-Took the amount as $200,000 instead of $220,000

Let's assume that 220.000  is supposed to be  220,000

Let  salesperson C  earn  E  during this period

Then  B  has earned  50% more than C  =  1.5C  = 1.5E

And A has earned  twice B  =   2B  = 2(1.5)C  =  3C  = 3E

So

A + B + C  = 220000

3E + 1.5E  + E   =  220000

5.5E  = 220000     [ divide both sides by 5.5 ] 

E  = 40000  =  amt  C  earned in the period

And B  earned   1.5C  = 1.5 (40000)    = 60000

So...in any one year, B's average earnings  = 60000 / 3  = 20000