The radius of the planet saturn is 6.03 × 107 m, and its mass is 5.68 × 1026 kg.
a. find the density of saturn (its mass divided by its volume) in grams per cubic centimeter. (the volume of a sphere is given by πr 3.)4 __3
b. find the surface area of saturn in square meters. (the surface area of a sphere is given by 4πr 2 .)

You wouldn't know it from reading the question,
but the volume of a sphere is
                                                       4/3 π (radius)³ .

So the volume of Saturn is

         (4/3 π) (6.03 x 10⁷ m)³  =  about     9.184 x 10²³ m³

and its density is      (mass) / (volume)

           = (5.68 x 10²⁶ kg) / (9.184 x 10²³ m³)

Sadly, we need this to be in units of  ' gram/cm³ ' so we need to
account for some conversion of units.

      = (5.68 x 10²⁶ kg) · (1,000 g/kg) / (9.184 x 10²³ m³) · (10⁶ cm³/m³)

     =  (5.68 x 10²⁹ grams)  /  (9.184 x 10²⁹ cm³)

     =       0.618  gram/cm³  .

Look at that !
The density of the planet Saturn is less than  ' 1 '.
If you had a big enough bathtub full of water, Saturn would float in it ! 

The surface area of a sphere is

                                       4  π  (radius)²

                                  =  (4 π) (6.03 x 10⁷ m)²

                                  =  (4 π) (36.4 x 10¹⁴ m²)

                                  =     4.57 x 10¹⁶ m²      

          

The answer would be a