Answer
Find out how many seconds faster has Alexandria's time then Adele's time .
To proof
Let us assume that seconds faster has Alexandria's time then Adele's time be x.
As given in the question
Adele Swam the length of the pool in 32.56 seconds. Alexandria swam the length of the pool in 29.4 seconds.
Than the equation becomes
x = 32.56 - 29.4
x = 3.16 seconds
Therefore the 3.16 seconds faster has Alexandria's time then Adele's time .
Hence proved