Question 1061244
It is assumed that all the painters paint at the same rate
Their rate of painting for 4 painters is:
[  1 house ] / [ 12 days ]
1 painter will paint at 1/4 of this rate, so
1 painter's rate = [ 1 house ] / 48 days ] 
3 painters will paint at 3 times this rate, so
3 painter's rate = [ 3 houses ] / [ 48 days ]
[ 3 houses ] / [ 48 days ] = [  1 house ] / [ 16 days ]
It will take 3 painters 16 days to paint the house
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I use a logical method, but there are formulas. I 
can see it more clearly using logic