I cant find the scale factor of this sphere

[HelpMeMyTeacherHatesMe]

Hey, my mind has just gone blank and for some reason I just cant find the scale factor of this question

< link to objectionable page removed >

I know its simple but it has been bugging me for ages.

Thanks

 

[stapel]

Hey, my mind has just gone blank and for some reason I just cant find the scale factor of this question <link removed>.
I know its simple but it has been bugging me for ages.

There are two exercises at the link. With which are you having difficulty?

Since you have spent "ages" on this, you have loads of work you can show us. Please include all of the steps in at least one of your efforts when you reply. Thank you!