Complementary probabilities

This task is about probability as a fraction.
 
a)

 

 The prizes in a raffle are either a supermarket voucher or a petrol voucher. The probability of getting a supermarket voucher is 35.

What is the probability of getting a petrol voucher?   __________
b) The pens in a pencil case are either blue, green, or red. The probability of getting:

  • a blue pen is 47
  • a green pen is 17

What is the probability of getting a red pen?   __________
c) The balloons given out at a birthday party are either purple, pink, orange, or yellow. The probability of being given:

  • a purple balloon is 511
  • a pink balloon is 111
  • an orange balloon is 211

What is the probability of being given a yellow balloon?   __________