Find the smallest three-digit number using the digits 4, 7, and 9.
(a) 974
(b) 497
(c) 479
(d) 794

Hint: Arrange the given three numbers from the smallest digit to the greatest digit. Use the smallest digit at the hundredth place and the greatest digit at the units place to get the smallest three-digit number.

Complete step-by-step answer:
We need to find the smallest three-digit number using the digits 4, 7, and 9.
To find the smallest three-digit number. We first arrange the given digits in ascending order, that is, from the smallest number to the greatest number.
Then, we assign the smallest digit to the hundredth place, the middle digit to the tenth place, and the greatest digit to the units place.
If the digits include a zero, then we interchange the positions of the hundredth place and the tenth place, otherwise, the number will become a two-digit number.
We arrange the numbers 4, 7, and 9 in ascending order as follows:
4, 7, 9
Now, we assign the smallest digit, 4, to the hundredth place.
4 _ _
Next, the middle digit is 7, hence, we assign it to tenth place.
4 7 _
Next, the greatest digit is 9, hence, we assign it to the units place.
4 7 9
We don’t have any zero in the digits, so the final answer for the smallest number formed from the digits 4, 7, and 9 is 479.
Hence, the correct answer is option (c).

Note: You can also analyze directly by observing the given options and then choose the smallest number containing the digits 4, 7 and 9 which is a shortcut-method