What is the answer to b?

===================================================
Explanation:
Pick any column and divide the weight over the length
column 1: 9/15 = 0.6
column 2: 12/20 = 0.6
column 3: 18/30 = 0.6
column 4: 30/50 = 0.6
The weight per cm is 0.6 grams per cm
---------
Another way you could look at is like so
9 g = 15 cm
9/15 g = 15/15 cm
0.6 g = 1 cm
We divided both sides by 15 to turn "15 cm" into "1 cm". Think of "per cm" as "per 1 cm". This works for any other column as well.
Answer:
[See Below]
Step-by-step explanation:
___________________________________________________
✦ To figure out the rule of this table you must Add, Subtract, Multiply, and Divide each line to find similarities.
___________________________________________________
✧ Line 1:
___________________________________________________
✧ Line 2:
___________________________________________________
✧ Line 3:
___________________________________________________
✧ Line 4:
___________________________________________________
So with this, we can conclude that each line has a similarity when we did:
___________________________________________________
So the weight per [tex]cm[/tex] is [tex]1.66[/tex] or [tex]g*1.66r[/tex].
~Hope this helps Mate. If you need anything feel free to message me.