Question 363478
"tom's weekly compensation consist of $300 plus 20 percent of his sales" = 300+0.20t
"Alison's weekly compensation consist of $200 plus 25 percent of her sales" = 200+0.25a.
Here we let t = Tom's weekly sales, a = Allison's weekly sales. 
"they both had the same amount of sales" means t = a.
 "and the same compensation for a particular week" means 200+0.25a = 300+0.20t.
By direct substitution, 200+0.25a = 300 + 0.20a, or
0.05a = 100, or a = 2000, the amount of sales of Allison, which is also the amount of sales of Tom.