Hi, ·
2 men and 6 boys can build a wall in 4 days, 4 men and 4 boys can do the same job in 3 days.
Let x an y represent one day's work for men and boys respectively
Question states***
2x + 6y = 1/4
4x + 4y = 1/3
-4x -12y =-1/2 ||multiplying 1st EQ thru by -2 to eliminate the x variable
4x + 4y = 1/3
-8y = -1/6
y = 1/48 and x = 1/16
,
, 
A man can do 1/16 of the work alone per day.
Would take a man
days to build the wall alone.
and
CHECKING our Answer***