Hint
Try a random number of over 50s to see what happens.
Answer
20,064 apples.
Reasoning
It doesn't matter how old the people are.
As only 3/4 of the over 50s claimed 16 apples, this averages out to 12 apples each.
Similarly, only 1/8 of the under 50s claimed 96 apples, this again averages out to be 12 apples each.
Therefore, the total number of apples was 1,672 x 12 = 20,064.
??
Puzzle 3
My BrainBashers electronic world atlas has developed another fault.
I listed five countries, and how far away each was from England, and here are the results:
Australia 500 miles
Peru 8,000 miles
India 4,500 miles
Scotland 9,500 miles
France ? miles