Explanation:We are given to find the unit digit of the product of the first 22 natural numbers.The first 22 natural numbers are 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22.The unit digit of a number is the digit in the one's place of the number. i.e It is the rightmost digit of the number. For example, the units digit 243 is 3Since the unit digit in two numbers among the first 22 natural numbers, that are 10 and 20 is 0, so the total product must have unit digit 0.? The unit digit of the product of the first 22 natural numbers will be 0.