It looks like there's a lot of extra information here. If the question only asks about the trip from Rohn to Nikolai, then the only information that matters is that the distance between the two is 121 km & that Seavey did it in 14 hours. Don't let the extra numbers throw you off.
As for the math behind this - km/hr is a math equation in and of itself. Any ratio like that is a simple division problem. Just plug your numbers (121 km / 14 hr) into the formula (km / hr) to get your answer!
EDIT: for future questions where they don't label it as clearly... velocity = the distance divided by the time.
Memory is a component of the brain where new information and old information are stored and can be retrieved very quickly.
There are two major types of memory:
1. Long-term memory
2. Short-term memory.
The Long-term memory is the place where information have been stored for a long time. This memory is what makes you remember your name, your house address, your favorite food, your class mate's names and other information.
The short-term memory on the other hand is the type of memory that stores events or information for only a short period of time. This explains why you can be introduced to five people, but ten minutes later, you only remember one name, or no names at all!
Events or memories that are in the Short-term memory can be made to enter the long term memory with the help of some techniques.
