In: Economics
To maximize the profit in the short run the firm will have to match the price and the marginal cost, here the price is $25 and the marginal cost is $20, the firm should increase the output to the point where the price and MC are equal. i.e. the MC will increase to P that is 425.
If the firm increase the output they will be maximizing the profit at the current price and it will increase the revenue. After increasing the output the firm will still be facing a negative profit as the MC and the price will be less than ATC.