54x+78(400-x)≤24000。
26x+4 1(400-x)≤ 12000
The solution is x≥300.
And ∵ 0≤x≤400, ∴ ∴300 ≤x≤400. ..
These 400 board houses can accommodate the victims w = 5x+8 (400-x) =-3x+3200.
When x=300, w gets the maximum value of 2300.
A: 400 board rooms can accommodate up to 2,300 people.