Remember that finding terms in a geometric sequence is done by multiplying the previous term by a common ratio . For example, we can say:
We have . To find
, let's multiply this term by
:
Now, let's use this to find all of our other terms:
Thus, our terms are 64, 80, 100, 125, and (625/4).
A generic odd number can be written as
Since there is an odd number every two numbers, three consecutive odd numbers will be
Now let's make up the equations: the sum of the first two is
And 27 less than 3 times the largest is
These two must be the same, so we have
Subtracting 4k and 3 from both sides gives
Which means that the problem has no solution.
To confirm this hypothesis, we can observe that, on the left hand side, we have the sum of two odd numbers, which is even
On the right hand side, we have an odd number, multiplied by 3 (still odd), take away 27 (still odd).
So, the left hand side is even, and the right hand side is odd. They can't be the same number.