20, 60 is the correct answer.
Below is the output of above code: (I have added extra statements to print for your clarity)
20 60
ptr: 6422040
arr: 6422034
ptr-1: 6422039
arr+1: 6422035
(&arr + 1): 6422040
In this we are assigning &arr+1 to ptr, not just arr+1, &arr+1 will return immediate next address after the end of the array. That's why ptr contains the value of the next location after the array.
You got under the impression that ptr was pointing to 20, but actually, it is pointing to memory location just after 60.
Hope this helps.