Question

PLEASE ANSWER

The probability that a student does work in pen is 0.5, the probability that a student does their math homework is 0.8, and the probability that a student chose to use pen to complete their math homework is 0.3. What is the probability that a randomly chosen student used pen or completed their math homework?

Answer 1

50% for pen

80% for homework

30% for both

(I don't know how they got 30% for both because it should be 40%.)