I just took my blood pressure it was 111/70 I am 78 yrs. old Is this good or low?

Sounds just about right how do you feel.
Blood pressure is just one indicator of your health I find the more I check the sicker I feel.
If you have a good energy level are eating a good diet don't get dizzy when you stand up or faint or feel like you're heads busting open when you do stand up or move quickly then your blood pressure is probably just fine.
Listen to the signs are body is giving you.
Good luck and stay active.