Answer:27
Step-by-step explanation:
Notice this is a geometric progression since each number multiplied by some factor equals the next number in the sequence, in this case,

Then by applying the formula for sum to infinity of a geometric progression,
How many red ones were in the bag?
Answer:
<em>-21 and 4</em>
Step-by-step explanation:
They multiply to a negative number, so you need a positive number and a negative number.