In an adult human, how many ribs are connected to sternum either directly or indirectly?

The ribs that are connected to the sternum either directly or indirectly, include 10 pairs of ribs. 

In an adult human, there are typically 12 pairs of ribs.

• The first 7 pairs of ribs (ribs 1-7) are considered true ribs because they are directly connected to the sternum via their own costal cartilages.
• Ribs 8, 9, and 10 are considered false ribs because their cartilages do not attach directly to the sternum. Instead, they attach to the cartilage of the rib above.
• Ribs 11 and 12 are called floating ribs because they do not attach to the sternum at all.