Let the number of bricks manufactured by company C = a
Number of baked bricks sold by company D = a - 4500
Number of baked bricks sold by company C = 80/(80+100) * (100 - 40)/100 * a = 4a/15
Now,
Number of baked bricks sold by company C - Number of baked bricks sold by company D = 100
4a/15 - (a - 4500) = 100
11a/15 = 4400
a = 6000
Number of baked bricks sold by company D = 6000 - 4500 = 1500
Number of baked bricks manufactured by company D = 1500 * (100+50)/50 = 4500
(X2 + Y2) = 4500
I: X + 10 = 2Y + 8
X = 2Y - 2
(2Y - 2)2 + Y2 = 4500
5Y2 - 8Y + 4 = 4500
5Y2 - 8Y - 4496 = 0
Y = 4(1 ± √1406)/5 (not possible)
II: 3X - Y = 75% of 200
Y = 3X - 150
X2 + (3X - 150)2 = 4500
X2 - 90X + 1800 = 0
(X - 30)(X - 60) = 0
X = 30, 60
Y = 3*30 - 150 = -60 (not possible)
Y = 3*60 - 150 = 30
The values of X are Y are positive integers.
III: 20% of (X + Y) = 540/(X - Y)
(X + Y)(X - Y) = 2700
X2 - Y2 = 2700
X2 + Y2 = 4500
From both equations -
X2 = 3600 => X = 60
Y2 = 900 => Y = 30
The values of X are Y are positive integers.
Hence option 'e' is correct.