Population below 35 years = 400 million = sum of below 15, 15--24, 25--34 groups.
Total percentage for below 35 years:
\[
30 + 17.75 + 17 = 64.75%.
\]
So total population = $\frac{400}{0.6475} \approx 617.16$ million.
Population below 15 years = $0.30 \times 617.16 \approx 185.15$ million.
Let males = $M$, females = $0.96M$, total = $M + 0.96M = 1.96M$.
So $M = \frac{185.15}{1.96} \approx 94.53$ million, females = $0.96M \approx 90.74 \ (\approx 90.8)$.
\[
\boxed{90.8 \ \text{million}}
\]