In an experimentation social interaction 4 people will sit in 4 seats in a row, in how many ways can this be

Ineed with this problem 21 show steps

The weight of a full steel bead tire is approximately 800 grams, while a fighter wheel weighs only 700 grams. what is the weight of each tire in pounds?

There are a total of 75 students in the robotics club and science club. the science club has 9 more students than the robotics club. how many students are in the science club?