The probability of rain each day in a week of 7 days is 0.7. What is the probability that there will be rain on Monday or Wednesday or Thursday?
Is that different from the probability of rain on Tuesday or Friday or Saturday?
What is the probability that there will be no rain that week?

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.