please help!

Question

1.) A random digit from 1 to 9 (inclusive) is chosen, with all digits being equally likely. The probability that when it's squared it will end with the digit 1.

2.) A random number between 1 and 20 (inclusive) is chosen. The probability that its square root will not be an integer.

Answer 1

See response to:
http://www.jiskha.com/display.cgi?id=1344678011

and post if you need more explanations or would like to post your attempt.

Answer 2

thank you for your help!
can you check if it's correct?

1.) 1/9
2.) 4/2= 1/5

Answer 3

1.
Note that
21*21=441
49*49=2401
Does that give you a hint?

2.
The question looks for
"The probability that its square root will not be an integer"
so check your answer accordingly.

Answer 4

Question: why is it not 2/9? Since I know 1 squared will be 1, which ends in 1, but what about 9? 9 squared is 81, it ends in 1. So that makes 2/9 = 0.22

Answer 5

Question: why is it not 2/9? Since I know 1 squared will be 1, which ends in 1, but what about 9? 9 squared is 81, it ends in 1. So that makes 2/9 = 0.22

@MathMate