If I am not very wrong than

X is the profit Tara earns on investing Y amount of money

(X-Y) is the profit earned by James over the same amount of money

2X/3 is the profit earned by Sara for Y amount of money invested

``````````````````````````````````````````````````

The total money in the money we have in the end

==(Y + X)+ ((X-Y) +Y) + (2X/3 + Y)8X/3 + 2Y