yah i agree kalanki bro, ma ni confused .. how are so sure the house next door is 13 or 11, it could have been 21??? wouldnt these be possible answers, like Dsharma said.. 36*1*1 (sum=38) 18*2*1 (sum=21) 9*4*1 (sum=14) 9*2*2 (sum=13) 6*3*2 (sum=11) 4*3*3 (sum=10) and by the way, we are one who is solving the problem not the census taker, so isnt it important for us to know the enough informaiton..