Amherst Co$.$ sells laptops for $$543$ and tablets for $$309.$ Amherst has $$722,000$ of fixed costs and incurs $$391$ of variable costs for each laptop it sells and $212$ of variable costs for each tablet it sells. Amherst Co$.$ sells $1$ laptops for every $5$ tablets. Assuming that sales ratio remains constant, how many tablets must Amherst Co$.$ sell to earn $$255,000$ of pre$-$tax income?