Answer: a) $17.31, b) $17.31.
Explanation:
Since we have given that
Total bill for four pairs of shoes = $69.24
Number of pairs of shoes = 4
We need to find the average price for each pair of shoes .
So, Average price would be

If he purchased only 1 pair of shoes, the amount he has to pay based on average price would be $17.31.
Hence, a) $17.31, b) $17.31.