Question 927563
The ratio of three person's investments = 300:400:500
                                        = 3:4:5
so first first person investment  = 3x 
second person investment  = 4x
third person investment  = 5x
they decide to split the profits in proportion of their investment
so ration of their profits = 3:4:5
total profit  = 3x+4x+5x = 12 x
Total profit is $ 1500
12x = 1500
 x= 1500/12
    =500/4
    = 250/2
      =125
so second person's profit  = 4 x= 4*125 = $ 500