Answer: There were 60 people in the picnic.
Step-by-step explanation:
Let there are x people in the picnic,
Since, the number of people who ate the hot dog for a lunch = 30 % of the total number of people in the picnic
= 30% of x
= 0.3 x
According to the question,
0.3 x = 18
⇒ x = 60 ( Dividing both sides by 0.3)
Thus, there were 60 people in the picnic.