Let the carpenter take n days to finish the job.
To Find: n
He builds 5 frames on day 1, 7 on day 2, 9 on day 3 and so on.
So it forms an AP 5, 7, 9, 11,… and so on.
We need to find the number of terms in this AP such that the sum of the AP will be
equal to 192
Given: Sum of AP = 192
He finishes the job in 16 days.