19) 217

Total number of air passengers in 2005 = 228 million

The text says that 9 in 10 passengers were international. So 1 in 10 must be domestic.

Number of domestic passengers = 0.1 x 228 = 22.8 million passengers.

Since each domestic passenger was counted twice, we need to divide 22.8 by 2.

So number of domestic passengers = 22.8 / 2 = 11.4 million.

Total number of passengers (international + domestic) = (228 – 22.8) + 11.4 = 216.6 million

To the nearest million, this is 217 million