Answer:
Tubul needs
1.45 L to paint interior of tank, and
1.21 L to exterior of tank
for a total of
2.66 L to paint both interior and exterior of the tank (except exterior base).
He needs an extra 0.66L to do a complete job!
Note: It is not clear if Tubul wants to paint the interior (important) or exterior (beautiful) or both (important and beautiful) surfaces of the tank.
Step-by-step explanation:
Given:
Tank
Height, h = 1.4m
Diameter, d = 1.1m
Paint required = 0.25L / m^2
Interior surface area,
Ai = pi*d^2/4 + pi*d*h (includes base, no cover)
= pi*1.1^2/4 + pi*1.1*1.4 = 0.95 + 4.84 sq.m
= 5.79 sq.m.
Paint required to paint interior
= 5.79 * 0.25
= 1.45L
exterior surface area,
Ax = pi*d*h (excludes base, no cover)
= pi * 1.1 * 1.4
= 4.84 sq.m.
Paint required to paint exterior
= 4.84 * 0.25
= 1.21L
Paint required to paint both interior AND exterior, except base of exterior
= 1.45 + 1.21
= 2.66L
