Prime ideals and quotient rings

Let R be a commutative ring with unity, let IβŠ†R be an ideal, and let Ο€:Rβ†’R/I be the natural projection homomorphism.

  1. Show that if β„˜ is a prime ideal of R/I, then Ο€βˆ’1(β„˜) is a prime ideal of R.
  2. Show that the assignment β„˜β†¦Ο€βˆ’1(β„˜) is injective on the set of prime ideals of R/I.