How many different ways are there to arrange the letters a, b, a, and b? 4

You can arrange them 16 times. Hope this helps!

the answer is:

the correct option is the option b.

to calculate the surface area of the right cylinder, we need to use the following formula:

from the picture we know that:

so, substituting and calculting we have:

hence, we have that the correct option is the option b.

have a nice day!