Question

Show an example of an irrational number between 9 and 11.

A. √99

B. √10

C. √100

D. √20

Answer 1

9^2 = 81
11^2 = 121
so it has to be between sqrt 81 and sqrt 121
the only ones are sqrt 99 and sqrt 100
sqrt 100 is no good because 10 is rational (20/2 for example)
so I think sqrt 99
A

Answer 2

B. √10

Answer 3

Yes, you are correct. √99 is an example of an irrational number between 9 and 11.