Answer:
For a cylinder of radius R and height H, the surface area is given by:
A = 4*pi*R^2 + H*(2*pi*R)
Where pi = 3.14
We can just use that formula for each one of the given cylinders.
1) We can see that the diameter is 10 yd, and the radius is half of the diameter, then the radius is:
R = 10yd/2 = 5yd
And the height is 3yd, then H = 3yd
Replacing these in the area equation, we get:
A = 4*3.14*(5 yd)^2 + 3yd*(2*3.14*5yd) = 408.2 yd^2
2) Here we can see that the diameter is 24 cm, then the radius is:
R = 24cm/2 = 12cm
And the height is H = 10cm
Then the area is:
A = 4*3.14*(12 cm)^2 + 10cm*(2*3.14*12cm) = 2,562.24 cm^2
3) In this case we have a radius equal to 12 cm, and a height equal to 7 cm, then the area is:
A = 4*3.14*(12 cm)^2 + 7cm*(2*3.14*12cm) = 2,336.16cm^2
4) Here is hard to see the measures, I think that here we have:
diameter = 8m
Then R = 8m/2 = 4m
And the height is also 8m, H = 8m
Then the area is:
A = 4*3.14*(4 m)^2 + 8 m*(2*3.14*4m) =401.92 m^2
is 
. If the length of the radius is tripled, then the circumference becomes 
, which is just 3 times the original circle's circumference.