1. X=90
Y=90
W=99
Z=90
90 x 1000 + 90 x 100 + 90 x 10 + 99 = 99999
X=90
Y=80
Z=70
W=65
90 x 1000 +80 x 100 + 70 x 10 + 65= 98765
X=10
Y=30
Z=50
W=79
10 x 1000 + 30 x 100 + 50 x 10 + 79 = 13579
X=10
Y=0
Z=20
W=46
10 x 1000 + 0 x 100 + 20 x 10 + 46 = 10246
2.x{ 0,1...9}
y{ 0,1.....9}
z{ 1,2}
q{ 0,1.....9}
3.MD < MC = 1500>1100
MMIII = MMIII = 2003=2003
XC < CX = 90<110
CMI < MCI = 901<1101