What is sets?

[Eight.]

When somebody says "You have to do three sets of Push-ups." What does it mean? How many push-ups in a set?

[eight]

10 .......

[RandomManJay]

Normally a set is like 8-10 push ups (or whatever it is your doing), then you wait for like a minute, then do another 'set', so you will do 10 push ups, then a minutes rest, then another 10, then rest again, then 10 more. So you've done 3 sets of 10 push ups. It's a technique so you don't strain yourself, and gives you the opportunity to change the times or weights you're using so you're not using times etc. which do nothing to you or are too strenious for you.