Let number of plastic containers collected by fourth grade= x
Then number of plastic containers collected by fifth grade students=x-216
OR
If number of plastic container collected by fifth grade is y
then number of plastic container collected by fourth grade=y+216
So, we can write it as follows
⇒ number of plastic containers collected by fourth grade= number of plastic containers collected by fifth grade +216
I'm pretty sure it's B you have it correct
Each number is 1/3 of the number before it.
After 18 come 6, 2, 2/3, 2/9, 2/27, 2/81, ... etc.
If the last number is supposed to be 500 then the pattern is times 5.
4*5=20
20*5=100
100*5=500
