You would expect airline DEF to provide more reliable service.
To solve this problem, you need to compare the percentage of delays of the two airlines. The airline with a lower percent delay is more reliable because it delays less often.
The percentage of delays for airline DEF is already given: 13%. Therefore, we need to determine the percentage for airline ABC.
Percentage is simply the ratio of two numbers multiplied by 100. To find the percent of delays if the airline has had 18 delays out of 126 flights, divide 18 into 126 and then multiply the result by 100.
18 / 126 = 0.142857
0.142857 x 100 = 14.2857%
Airline ABC has a 14.2857% delay percentage rate, whereas DEF is 13%. Since 13 is a lower number than 14.2857, DEF would be expected to be more reliable.