?? c ) For a given personal allowance of ?? % , the standard time for the operation ?? = ?? ?? enter

$\mathrm{â??}$c$)$ For a given personal allowance of $\mathrm{â??}\%,$ the standard time for the operation$\mathrm{â??}=$ 

$\mathrm{â??}\mathrm{â??}$

enter your response here minutes $\mathrm{â??}($round your response to three decimal$\mathrm{â??}$ places$).$