Question

which of the following cannot be a unit digit of a perfect square 6 ,1,9,8​

Answer 1

Answer:

(d)8

Explanation: According to the property of a perfect square a number ends unit digits in 2,3,7 and 8.

Answer 2

Answer:

hey guys your answer is 8.

$hope \: you \: like \: it.$

Step-by-step explanation:

It is very easy to predict the ones digit of the square of any number, N:

• If N ends with a zero, its square N^2 must end with zero.
• If N ends with a one, its square N^2 must end with one.
• If N ends with a two, its square N^2 must end with four.
• If N ends with a three, its square N^2 must end with nine.
• If N ends with a four, its square N^2 must end with six.
• If N ends with a five, its square N^2 must end with five.
• If N ends with a six, its square N^2 must end with six.
• If N ends with a seven, its square N^2 must end with nine.
• If N ends with an eight, its square N^2 must end with six.
• If N ends with a nine, its square N^2 must end with one.
• The only possible ones-digits for a perfect square are: [014569].

Therefore, a perfect square cannot end with: [2378].

Also note that the square root is irrational, for any number that ends in 2, 3, 7, or 8.