You may think this is a tricky question because there are a lot of numbers given. However, it is quite simple!
Think of it this way.
A child is tested positive for a disease. S/he can either be true positive or false positive.
Number of true positive cases = 72
Number of false positive cases = 92
Total number of positive cases = 164
We are looking for the probability of child having the disease (true positive).
Probability of true positive out of all positives = 72 out of 164 which is 44%