Question

Write the possible unit’* digits of the square root of the following numbers. Which of these numbers are odd square roots?
(i) 9801
(ii) 99856
(iii) 998001
(iv) 657666025

Answer 1

(i) 9801

Since, unit digit of 9801 is 1

(\therefore) Unit digit of square root = 1 or 9

Since the number is odd, square root is also odd

(ii) 99856

Since, unit digit of 99856 = 6

(\therefore) Unit digit of square root = 4 or 6

Since the number is even, square root is also even

(iii) 998001

Since,unit digit of 998001 = 10

(\therefore) Unit digit of square root = 10 or 9

Since the number is odd, square root is also odd

(iv) 657666025

Since, unit digit of 657666025 = 5

(\therefore) Unit digit of square root = 5

Since the number is odd, square root is also odd