Question 841664
Examine for one bedroom first, and then multiply by 4.


Note the description, the WALLS will be painted.  This seems to indicate not the cielings and not the floors.  


The wall area of a room:   {{{12*8*2+10*8*2=8*2(12+10)=8*2*32=highlight_green(512)}}} {{{ft^2}}};
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Not all of that value is actual area or to be painted.  We subtract the required {{{65*ft^2}}} from that value:
Actual area of room to paint: {{{512-65=highlight_green(447*ft^2)}}}.


House has FOUR bedrooms to be painted:
{{{447*ft^2*4=highlight(1788)}}} square feet area to paint.