Answer: We are given:
During the first 10 days, the stock increases by $0.30 per day.
During the next 10 days, the stock decreases by $0.45 per day.
During the last 10 days, the stock increases by $0.25 per day.
We have to find total amount the stock increase over the first 10 days.
The total amount the stock increase over the first 10 days is:



Therefore, during the first 10 days the stock was increased by $3.