If I'm given a graph showing the market for a duopoly with:

prices ($0 through $10) on the y-axis, quantity (0 thorugh 10) on the x-axis, MC as a horizontal line at $6, a downward sloping demand curve (starting at price of $10, crossing through MC at $6, and ending at quantity 10), a downward sloping MR curve (starting at $10, crossing through MC at $6, and ending at quantity 5), dotted line going up from quantity 4 and stopping at $6 (where MC crosses demand), a dotted line going up from quantity 2 and stopping at $8 (where it reaches demand curve) and continuing the dotted line left to $8 at y-axis.

How do I go about finding the market outcome / price and quantity if the 2 firms compete, collude, merge, and then the merged monopolist is broken into 10 identical firms?