The total number of patients experienced unwanted side effects is 48
<u><em>Explanation</em></u>
60 patients are given drug A and drug A has unwanted side effects in 40% of the cases.
So, the number of patients experienced side effects for drug A = 40% of 60 
Now 80 patients are given drug B and it has side effects in 30% of the cases.
So, the number of patients experienced side effects for drug B = 30% of 80 
So, the total number of patients experienced unwanted side effects 