How can I randomly select one variable between 3 variables?

I want to randomly select 1 variable between variables 10, 20, and 30.

This is what I did and it failed.

a = [10:10:30]

rand(a)

It gives me numerous floats. I want to get 10 or 20 or 30.

Thank you for your help.

Answer 1

[Fangjun Jiang]

a = [10:10:30]
a(randi(3,1))

[Hwajin Choi]

Many Thanks!