10 emails = .01GB, ~= 1MB/email. Since when was a simple text email worth 1MB, unless you're writing a novel?
10 emails w/ photo attachments = .10GB, ~= 10MB/email_w/_photo. So 1 picture, taken by a cameraphone, which compresses the files to .jpg, is 10MB? HAH!
10 emails w/ attachments = .08GB, ~= 8MB/attachment. What exactly are we attaching here? A 10-page report with graphs and Excel embedded .docx file is barely 500KB.
.5 Hours streaming music = .43GB, ~= 251 KB/s. I'm sorry, but they don't even stream higher than 128kbps, on average, for desktops (Pandora).
10 pages of website = .05GB, ~= 5MB/page. This, actually, is debatable. Although highly unlikely each page is 5MB worth (unless you're going through a picture-heavy site, like DeviantArt)...
1 App/Game/Song = .12GB, ~= 123MB/file. Are you CRAZY? Apps and games are in KILOBYTES, barely reaching MEGAbytes, and compressed mp3 songs average at 5MB!
10 social media posts with photos = .14GB, ~= 14MB/post_w/_pics. Again, a big LOL if you think your photo, taken by a cameraphone, is ~14MB.
1 Minute streaming video = .06GB, ~= 1MB/s ~= 1000KB/s. Videos suitable for the small screen size of your smartphone shouldn't be at 1000KB/s. Heck, even 300KB/s, encoded properly, will look super fine, so assuming 1000KB/s to stream such a video? Laughable.