What are the pips and skin of an orange?
The skin is the outer thick orange-coloured cover; obviously as you're not told to remove it this would include the pith (the white fibrous material) as well. The pips are the seeds inside the fruit:


  pip
  
  noun
  
  plural noun: pips
  
  1.
  a small hard seed in a fruit.
  
  synonyms:  seed, stone, pit