Rainbow Paints is discontinuing a line of paint that it purchased at $$54$ less $50\%$ and $10\%$ per $4-$L pail. The store$$s overhead is $40\%$ of cost$,$ and normal operating profit is $20\%$ of cost$.$ If the manager of the store is prepared to accept a loss of one$-$quarter of the overhead expenses, what markdown rate can the store offer in order to clear out the paint? $($Do not round intermediate calculations and round your final answer to $1$ decimal place.$)$

Rate of markdown

$\%$