1^2 and 9^2 end in 1
2^2 and 8^2 end in 4
3^2 and 7^2 end in 9
4^2 and 6^2 end in 6
5^2 ends in 5
So, perfect squares cannot end in 2,3,7,8
So the only possible choices are 56 and 99
Can you narrow it down any more than that?
Which of the following could be the last 2 digits of an integer that is a perfect square? What is your reasoning?
12
23
56
87
99
3 answers
I got that far, and I selected 99, but the answer is 56, and I'm not sure why. Could you please help me understand this?
well, 16^2 = 256
0 answers