Answer:
7
Step-by-step explanation:
To find how many Austin got incorrect, we can start by finding how many he gets correct.
We can express 72% as the fraction 72/100.
Now solving we achieve, 72/100 * 25.
By cancelling, the answer is 18. But that is how many are correct.
We subtract 25 - 18 to reach our answer of 7.