This whole question is based on you being able to use the normal distributions chart. If you don't know this, this is where you should start.
In general, for any distribution you ask what are the chances that my
random variable X will take a certain value.
You know for a normal distributed variable that itīs 50% chance of getting a value under/over the mean. They say for example that itīs about 68% chance of X taking values between mean minus one std. dev. and mean plus one std. dev.
All this you can find for yourself exactly in this table I am talking about.
Try the following link:
Public Domain Normal Distribution Table