Question

An airplane was travelling with 481 passengers. when it arrived atb the airport some passengers got off and 30 people got on an airplane. at the next airport hal the passengers got off the plane and 70 pwople got on an airplane. there were now 220 passengers on an airplane

Answer 1

If you're looking for how many got off at the first airport, what you should do is start backwards.

220 passengers
-70 passengers
you now have 150 passengers.
multiply that by 2 because you have half of the passengers

300 passengers
-30 passengers
you now have 270 passengers.

481 passengers
-270 passengers
you end up with 211 passengers getting off at the first airport.
I hope this helps!