Total surface area of cylinder = 2πr(h + r)
Given that, r = 14/2 = 7 cm, h = 40 cm

Correct Option: A

Total surface area of cylinder = 2πr(h + r)
Given that, r = 14/2 = 7 cm, h = 40 cm
∴ Required total surface area = 2 x (22/7) x 7 x (40 + 7)
= 44 x 47 = 2068 sq cm

Given, r = 7 cm, h = 80 cm
Volume = πr²h = (22/7) x 7 x 7 x 80

Correct Option: C

Given, r = 7 cm, h = 80 cm
Volume = πr²h = (22/7) x 7 x 7 x 80
= 12320 cm³

Here, k = 12%
According to the formula,
Percentage increase in volume = [(1 + k/100)³ - 1] x 100%

Correct Option: A

Here, k = 12%
According to the formula,
Percentage increase in volume = [(1 + k/100)³ - 1] x 100%
= [(1 + 12/100)³ - 1] x 100%
= [(1.12)³ - 1] x 100%
= 0.404928 x 100% = 40.4928%

Here, x = y = -19%
According to the formula,
Percentage decrease in surface area
= [x + y + xy/100]%

Correct Option: D

Here, x = y = -19%
According to the formula,
Percentage decrease in surface area
= [x + y + xy/100]%
= [- 19 - 19 + (-19) x (-19) /100]%
=[-38 + 361/100]%
= [-38 + 3.61]% = -34.39 %

Surface area of 1 brick
= 2 (lb + bh + lh)
= 2(22.5 x 10 + 10 x 7.5 + 7.5 x 22.5)
= 2(225 + 75 + 168.75)
= 2 x 468.75 = 937.50 cm²
= 93750/(100 x 100) = 0.09375 sq m
∴ Number of bricks = Total area/Surface area of 1 brick

Correct Option: A

Surface area of 1 brick
= 2 (lb + bh + lh)
= 2(22.5 x 10 + 10 x 7.5 + 7.5 x 22.5)
= 2(225 + 75 + 168.75)
= 2 x 468.75 = 937.50 cm²
= 93750/(100 x 100) = 0.09375 sq m
∴ Number of bricks = Total area/Surface area of 1 brick
= 9.375 / 0.09375 = 100