# Aptitude - Square Root and Cube Root - Discussion

### Discussion :: Square Root and Cube Root - General Questions (Q.No.14)

14.

How many two-digit numbers satisfy this property.: The last digit (unit's digit) of the square of the two-digit number is 8 ?

 [A]. 1 [B]. 2 [C]. 3 [D]. None of these

Explanation:

A number ending in 8 can never be a perfect square.

 Pawan Goyal said: (Oct 26, 2010) hw this could be possible that a number ending with is not a perfect square

 Kala said: (Aug 13, 2011) Please explain.

 M.V.Krishna/Palvancha said: (Sep 11, 2011) Hello pawan and kala. The two digit numbers are from 10 to 99. The numbers with 8 in units place are. 18, 28, 38, 48, 58, 68, 78, 88, 98. These numbers do not have a perfect square (s*s). So answer is none of these. Hope you understand.

 Veena said: (Nov 9, 2012) Number ending with 0, 1, 4, 5, 6, 9 are the perfect squares rather than these are not perfect squares.

 Aarti said: (Feb 5, 2015) Number ending with 8 is not a perfect square.

 Balu said: (Jul 5, 2015) I can't understand so please explain again.

 Abi said: (Feb 10, 2016) 2 = 4. 3 = 9. 4 = 16. 5 = 25. 7 = 49. 9 = 81. 10 = 100. As you can see all squares have 0, 1, 4, 5, 6, 9 in units place. So if we have 2, 3, 7, 8 in units place it square root is not perfect.

 Jayram said: (Jul 19, 2016) If the units place is 1, 2, 3, 4, 5, 6, 7, 8, 9. Square of all number = 1, 4, 9, 16, 25, 36, 49, 64, 81. Then, take unit value for all squares =1, 4, 9, 6, 5, 6, 9, 4, 1. And approx is 2, 3, 7, 8.