How to sum values based on a drop-down list?

[GerganaG]

Hello! So now I will explain myself better. I'm doing this for a school project but I am not sure about the formula. I am doing reference about sold mobile phones in a techno shop. But I have made a drop-down list for the models of the mobile phones because, you know, there are a lot of different kinds. I have made a column about the number of the phones at the beggining of the month. Here's a picture to understand me better:
Untitled11.png

So what I want to do is to sum all of the phones at the beggining of the month. I'll give an example. Here is the formula I have used for cell E4:
Untitled2.png

What I want to do is to basically sum these values so 40+50+30+40=160. So we have 160 mobile phones brand Huawei. I want to sum the numbers of iPhone,Samsung,LG,Nokia the same way. Let's say that they are 300,200,450,150. So the result i want to get at cell C11 is the total number of the mobile phones at the beginning. Basically 160+300+200+450+150=1260. This was just an example. I really hope you understood me. It's really important. Is there a formula for this? Thank you in advance!

P.S. I have posted this thread on other forums as well. Here are the links:
https://www.mrexcel.com/forum/excel-questions/1005216-how-sum-values-based-drop-down-list.html
https://answers.microsoft.com/en-us/msoffice/forum/msoffice_excel-mso_windows8/how-to-sum-values-based-on-drop-down-list/eb382430-4126-4e93-aca8-fb3f19a77ac0?tm=1494766849944

[AlKey]

Your post does not comply with Rule 8 of our Forum RULES. Do not crosspost your question on multiple forums without including links here to the other threads on other forums.

Cross-posting is when you post the same question in other forums on the web. The last thing you want to do is waste people's time working on an issue you have already resolved elsewhere. We prefer that you not cross-post at all, but if you do (and it's unlikely to go unnoticed), you MUST provide a link (copy the url from the address bar in your browser) to the cross-post.

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Read this to understand why we ask you to do this, and then please edit your first post to include links to any and all cross-posts in any other forums (not just this site).

[GerganaG]

Your post does not comply with Rule 8 of our Forum RULES. Do not crosspost your question on multiple forums without including links here to the other threads on other forums.

Cross-posting is when you post the same question in other forums on the web. The last thing you want to do is waste people's time working on an issue you have already resolved elsewhere. We prefer that you not cross-post at all, but if you do (and it's unlikely to go unnoticed), you MUST provide a link (copy the url from the address bar in your browser) to the cross-post.

Expect cross-posted questions without a link to be closed and a message will be posted by the moderator explaining why. We are here to help so help us to help you!

Read this to understand why we ask you to do this, and then please edit your first post to include links to any and all cross-posts in any other forums (not just this site).

I am really sorry. I was in a rush. I will read the rules when i have time and try not to break them next time. I am sorry again!

[Jacc]

Just through in a link and you'll be fine.