So,
1400 people in total. Though, subtract 200 for the amount of extra adults. This makes 1200. Divide that by two. You get 600
You need to add 200 to the 600 to get the amount of adults. The amount of adults on board is 800.
The amount of children on board is 600.
600 plus 800 equals 1400, it makes sense. :P
