B. b=5; l=6; H=18
Feedback Let breadth = x metres, length = 3x metres, height = H metres.
Area of the floor=(Total cost of carpeting)/(Rate) = (270/5) sq.m = 54 sq.m
x×3x2=54⇒x2=54×2⇒x=6
So, breadth = 6 m and length =3(6)/2 = 9 m.
Now, papered area = (1720/10) = 172 sq.m
Area of 1 door and 2 windows = 8 sq.m
Total area of 4 walls = (172 + 8) sq.m = 180 sq.m
2×(9+6)H=180⇒H=6