Answer: 4500
Explanation:
Let x be the total number of staplers produced in a day.
Given : At a certain factory 10% of staplers produced on Monday were defective and 2% of the non defective staplers were rejected by mistake.
i.e. The probability of staplers non defective staplers were rejected by mistake = 0.02
Now, If 90 of the non defective staplers were rejected, then to find the total number of staplers produced that days is given by :-

Hence, the total number of staplers produced that day is 4500.