12. What is a perfect square number?
a. It is a number which can be expressed as a product of a number and itself.
b. It is a number which can be expressed as a ratio of two numbers.
c. It is a number whose only factors are the number and itself.
d. It is a number which cannot be expressed as a ratio of two numbers.

13. Which of the following will NOT result to a rational number?
a. √9
b. √1
c. √0
d. √2

14. In the statement √ = , which represents the square root of a number? a. a
b. b
c. √
d. 2

15. Which of the following numbers must be put under the radical sign in order to have a rational number?
a. any integer
b. any fraction
c. any perfect square
d. any square root

16. Between what perfect squares does 18 lie?
a. 16 and 20
b. 9 and 16
c. 16 and 25
d. 17 and 19

17. Between what integers does √27 lie?
a. 26 and 27
b. 25 and 36
c. 3 and 4
d. 5 and 6

18. Which of the following statements is true?
a. √7 > 3
b. √7 < 3
c. √7 < 2
d. √7 > 6

19. Arrange these numbers in increasing order: 5, √24, 6, 4.
a. 4, 5, 6, √24
b. 4, 5, √24, 6
c. 4,√24, 5, 6
d. √24, 4, 5, 6

20. On a number line, where should you put the point with coordinate √15?
a. between 2 and 3
b. between 3 and 4
c. between 4 and 5
d. between 5 and 6 ​