Answer:
![Y = 400 p](https://img.qammunity.org/2021/formulas/business/high-school/6t70je3wu535qe4grz19hii5noph9due3c.png)
Step-by-step explanation:
Given that ;
The total cost for 100 firms is TC :
![2+ (y_2)/(2)](https://img.qammunity.org/2021/formulas/business/high-school/tphfzh80bp9sr9ngizfrm3v5uv3up4jawg.png)
The marginal cost of one firm will be:
![MC_1 = (\delta \ TC)/(\delta y)](https://img.qammunity.org/2021/formulas/business/high-school/6k9ynfkvkb20g8o8kfth08w10a7kytvctb.png)
![MC_1 = (\delta \ ( 2+ (y_2)/(2)))/(\delta y)](https://img.qammunity.org/2021/formulas/business/high-school/eue5wdiacunwmilimewm88t50ediu86jh8.png)
![MC_1 = y](https://img.qammunity.org/2021/formulas/business/high-school/wrheutvfepxbn7xg3591qkvfkkflaaptrt.png)
So; Now , the marginal cost for the all 100 firms is
![100 \ MC_1 = 100y = Y_1 = 100 P](https://img.qammunity.org/2021/formulas/business/high-school/ii8pnmj9s1ewwz8eigvkqiyow6txp3ssco.png)
The total cost for 60 firms is
![TC_2 =(y^2)/(10)](https://img.qammunity.org/2021/formulas/business/high-school/ajk7mpzswd3z29nx7vbrqy30s3ez17c8np.png)
The marginal cost of one firm will be:
![MC_2= (2y)/(10)](https://img.qammunity.org/2021/formulas/business/high-school/cyysutnna1dcb0ez2cq7b9qk39ni1vvchy.png)
![MC_2= (y)/(5)](https://img.qammunity.org/2021/formulas/business/high-school/gpc4nxoccj0ke64mkjlbkk057bwsfbcdt8.png)
The marginal cost for all the 60 firms will now be:
![60*MC_2 = 60 * (y)/(5)](https://img.qammunity.org/2021/formulas/business/high-school/xjcstt8mdhteh2gqgmphxl76lgtb5hehsy.png)
![5*60*MC_2=60y](https://img.qammunity.org/2021/formulas/business/high-school/kzhzhdixej39f32521aaijutfrtqbcg2pl.png)
![300MC_2 = 60 y = Y_2 = 300P](https://img.qammunity.org/2021/formulas/business/high-school/t1tmp0r5hz5a2pt3xd95e5luaqb20dixdo.png)
Finally; the long run supply function is industry supply function and which is therefore determined as :
![Y = Y_1 +Y_2](https://img.qammunity.org/2021/formulas/business/high-school/4810igb6yoq6vvqskh64pj86wcze0lxgi1.png)
![Y =100p+ 300 p](https://img.qammunity.org/2021/formulas/business/high-school/l17ottz116dvxzz92syj1v8k2jmelf0vo3.png)
![Y = 400 p](https://img.qammunity.org/2021/formulas/business/high-school/6t70je3wu535qe4grz19hii5noph9due3c.png)