Help answering this math question

The people who recalled at least 1 dream from Group Y consist of 11 (people who recalled 1-4 dreams) + 68 (people who recalled 5+ dreams) or 79. Therefore, option B is the answer.
Answer:
79/164 or 0.482
Step-by-step explanation:
No. of people who recalled atleast one dream = 200 - 36 = 164
No. of people who recalled atleast onde dream from Group Y = 100 - 21 = 79
P(GroupY/atleast one dream)
= n(Group Y & atleast one dream)/n(atleast one dream)
= 79/164
or 0.482 (3sf)