Answer:

Step-by-step explanation:
Combining like terms:


Answer:
Step-by-step explanation:
r = 
Using the geometric series formula for the <em>n</em>th term:

Answer:
60
Step-by-step explanation:
because half of children is 50. 120÷50=60
So 5 liters of natural for every 7 synthetic, so 5 / 12 liters are natural oil.
so; 684 × (5/12) = 285 liters of natural oil
Hope this helps!