Question

what could be the possible ones digit of the square root of each of the following numbers? I) 1801 ii) 856 iii) 1008001 iv) 6577525​

Answer 1

Answer:

the correct answer is 5

Answer 2

Given: The numbers 1801, 856, 100801 and 6577525 are given.

To find: The possible ones digit of the square root of these numbers

Explanation: The square of the one digit number are as follows:

1-> 1

2->4

3->9

4->16

5->25

6->36

7->49

8->64

9->81

Now, looking at the square root of the above squared numbers, we observe:

The square root of numbers ending with 1 can have units digit 1 or 9

The square root of numbers ending with 4 can have units digit 2 or 8

The square root of numbers ending with 9 can have units digit 3 or 7

The square root of numbers ending with 6 can have units digit 4 or 6

The square root of numbers ending with 5 can have units digit 5

Looking at numbers given in question:

1801- It ends with 1 , therefore the units digit of its square root can be 1 or 9

856- It ends with 6 , therefore the units digit of its square root can be 4 or 6

1008001- It ends with 1 , therefore the units digit of its square root can be 1 or 9

6577525- It ends with 5 , therefore the units digit of its square root can be 5

Therefore, units digit of the square root of the numbers 1801,856,1008001 and 6577525 can be 1 or 9, 4 or 6, 1 or 9 and 5 respectively.