A defective briefcase costing Rs 800 is being sold at a loss of 8%.

C. $\mathrm{P}$ of the briefcase $=$ Rs. 800

Loss $=8 \%$

S. P $=$ CP $\left(\frac{100-\text { loss } \%}{100}\right)$

$=800\left(\frac{100-8}{100}\right)$

$=800 \times 0.92=$ Rs. 736

If the $p$ rice is further reduced by $5 \%$, the $s$ elling price of the briefcase will be

$=$ Rs. $\left(736-736 \times \frac{5}{100}\right)$

$=736\left(\frac{100-5}{100}\right)$

$=736 \times 0.95$

$=$ Rs. $699.20$

Thus, the selling price of the briefcase will be Rs 699.20.