For any natural n,the digital root of 7n cannot be.
Answers
Answer:
A Perfect cube Number
Step-by-step explanation:
Digital root is sum of numbers. So, Digital Root of 356 is 5.
3 + 5 + 6 = 14 -> 1 + 4 = 5
Now, as per properties of Digital Root, for a perfect cube number digital root will be 1,8 or 9. We will never have 7 here.
Consider some examples :-
729 (Perfect Cube of 9) = 7 + 2 + 9 = 18 -> 1 + 8 -> 9
So digital cube of 729 - 9
Similarly, digital root of other perfect cube numbers are as follows:-
1 (Perfect Cube of 4) -> 1
8 (Perfect Cube of 2) -> 8
27 (Perfect Cube of 3) -> 9
64 (Perfect Cube of 4) -> 1
125 (Perfect Cube of 5) -> 8
216 (Perfect Cube of 6) -> 9
You will never find 7 here as digital root.
So natural number n if it has a digital root of 7, it will never be perfect cube number.
Step-by-step explanation:
for any natural number 'n' the number 7n cannot end with the digit