A, B, C started a business with their investments in the ratio 1 : 3 : 5. After 4 months, A invested the same amount as before and B as well as C withdrew half of their investments. The ratio of their profits at the end of the year is ?

Let their initial investments be x, 3x and 5x respectively
Then,
$$ = {\text{A}}:{\text{B}}:{\text{C}}$$
$$ = \left( {x \times 4 + 2x \times 8} \right)$$     : $$\left( {3x \times 4 + \frac{{3x}}{2} \times 8} \right)$$     : $$\left( {5x \times 4 + \frac{{5x}}{2} \times 8} \right)$$
$$\eqalign{ & = 20x:24x:40x \cr & = 5:6:10 \cr} $$