A biased spinner has the following scores written on it 1, 2, 3 and 4. Such that the probability that the score is 1 is 0.3 and the prob that the score is 2 is 0.6.

Ben spins the pointer once

1) what is the prob he scores 1 or 2?

Is it 0.3 + 0.6 = 0.9

2) he scores 3 or 4?

Is it 1 - 0.9 = 0.1

Rachel spins the pointer twice

3) What is the prob the score is 1 both time?

Is it 0.3 x 0.3 = 0.09

4) What is the prob the score is 2 exactly once?

NOT SURE HOW TO DO THIS ONE