Rank the following in order from least precise to most precise. 915 meters, 21000 grams, 8.43 inches, and 5.426 seconds

There are 20 children in the cast of a class play and 8 of the children are boys of the boys 4 have a speaking part in the play and of the girls 8 do not have a speaking part in the play if a child from the cast of the place chosen at random what is the probability that the child has a speaking part

Alogical argument that is presented in graphical form using boxes and arrows is called?

Can someone factor this fully? my friend and i have two different answers and i would like to know if either of them is right. you in advance. a^2 - b^2 + 25 + 10a