Three independent samples are taken from the normal random variable of part B (μ = 60, σ = 20). Determine the probability that the average of the three samples is less than 25.

I'm reviewing for the FE exam, and this one showed up. I simply have no clue where to begin. The hint says to look at Central Limit Theorem, which shows what should happen for extremely large n. I don't understand how that helps, though, since 3 is not extremely large. I've taken an introductory course on probability, so I know some of the basics (such as distributions, means, standard deviations, look up tables, etc.), but this type of problem never surfaced, nor was it taught. Compounding the issue, I don't even know what to google to find related information -- a name for this type of problem (you can probably tell by my bloated title).

Feel free to give a solution or a nudge in the right direction