Question

1. What could be the possible 'one's' digits of the square root of each of the following
numbers?
(1) 9801 (ii) 99856
(iii) 998001 (iv) 657666025
​

Answer 1

Answer:

Step-by-step explanation:

(i)  1 or 9

( 1*1=1 and 9*9=81 ends at 1)

(ii)  4 or 6

(4*4=16 and 6*6=36 ends at 6)

(ii) 1 or 9

(same as (i) )

(iv) 5

( 5*5=25 ends at 5)

Answer 2

Answer:

Solution:

i. We know that the unit’s digit of the square of a number having digit as unit’s

place 1 is 1 and also 9 is 1[92=81 whose unit place is 1].

∴ Unit’s digit of the square root of number 9801 is equal to 1 or 9.

ii. We know that the unit’s digit of the square of a number having digit as unit’s

place 6 is 6 and also 4 is 6 [62=36 and 42=16, both the squares have unit digit 6].

∴ Unit’s digit of the square root of number 99856 is equal to 6.

iii. We know that the unit’s digit of the square of a number having digit as unit’s

place 1 is 1 and also 9 is 1[92=81 whose unit place is 1].

∴ Unit’s digit of the square root of number 998001 is equal to 1 or 9.

iv. We know that the unit’s digit of the square of a number having digit as unit’s

place 5 is 5.

∴ Unit’s digit of the square root of number 657666025 is equal to 5.

Step-by-step explanation: