Answer
Approximately 42.35ml.
Work Step by Step
Since NaOH is a strong base, and HNO3 is a strong acid, we can use this formula for a titration:
$C_1 * V_1 = C_2*V_2$
$0.085 * V_1 = 0.09 * 0.04$
$V_1 = \frac{0.0036}{0.085}$
$V_1 \approx 4.235 \times 10^{-2} L \approx 42.35 ml $
