Remove spacing between <p>

For first <p> set: margin-bottom:0; and for second <p> set: margin : 0; padding-top:0; simultaneously. It shoud be like:

<p style="margin-bottom:0;">
    test
</p>
<p style="margin : 0; padding-top:0;">
    test
</p>

That space isn't between the paragraphs. that's the space given to the characters themselves. Type has white space around it (partially to accommodate ascenders and descenders).

If you want to remove the space between the lines of text themselves, then you need to put the text into the same paragraph, and adjust the line height.

But even then, note that you'll never get this exact, as every typeface and font is going to have different metrics, and you won't always know what exact font will be shown on the end-user's screen. Using a web font will make things a bit more predictable for you.