So all you gotta do is substitute the radius and height into the formula-
S.A = (pi x r x L) + (pi x r^2)
The radius from the picture is 4.5 mm and the length is 20 mm
Also the value of pi is 3.14 approx
So SA = (pi x 4.5 x 20) + (pi x 4.5^2) = 282.74 + 63.62
Which is equal to 346.36 approx
Since the question says round to the nearest tenth your answer would be 350