According to the given information, Antra earned 28 euros per passenger and received a 30 euro tip. So, her total earnings per passenger can be calculated as:
Earnings per passenger = (28 euros + 30 euros) = 58 euros
Now, we know that Antra earned a total of 282 euros. To find the number of passengers (x), we can divide her total earnings by the earnings per passenger:
Number of passengers (x) = Total earnings / Earnings per passenger
x = 282 euros / 58 euros
x = 4.86
Since the number of passengers must be a whole number, we can round up to the nearest integer. Therefore, Antra had 5 passengers.