user17044: With https://blockchain.info/tobtc?currency=USD&value=10
I find that $10 = 0.01724138 BTC
And with https://data.bter.com/api/1/ticker/drk_btc
I find that 1 DRK = 0.017669 BTC
How can I get from those two bits of info $10 worth of DRK?
Also, Is there an equivalent site like blockchain.info for each coin?

user4276: Though TimS's method works, I always prefer to find the conversion factor. In this case, you want to know DRK per USD, or how much DRK will 1 USD buy.

Simplify your BTC/USD factor

0.01724138 BTC      .00172414 BTC    
--------------   =  -------------  
    10 USD              1 USD


Set up the conversion factor you are targeting. In this case, we want DRK on top and USD on bottom

.00172414 BTC          1 DRK
-------------   x   -------------  
    1 USD           .01766900 BTC


The BTC unit cancels out and we are left with:

.00172414       1 DRK       .0975798290 DRK
---------   x   -----   =   ---------------
.01766900       1 USD           1 USD



So 1 USD will buy you about a tenth of 1 DRK. Notice I added two extra decimals than the typical 8; this will account for up to three digit values that you want to multiply the factor by, because you loose decimals with every 10th.
Now you have the conversion factor and you can multiply it by any USD amount (that I assume you are considering investing) to get exactly how much DRK that will work out to. In this case, you said 10 USD so

.0975798290 * 10 = .9757982900


We round that off to eight decimals and you get your amount. 10 USD will buy .97579829 DRK.

user12034: Simple multiplication will find that:
0.01724138 BTC / 10 USD * 
1 DRK / 0.017669 BTC =
0.01724138/10/0.017669 DRK/USD ~=
0.975798 DRK / 10 USD

10 USD is just under 1 DRK.

Also, Is there an equivalent site like blockchain.info for each coin?

Most altcoins do have one or more block chain browser/explorer sites. Searching for "[altcoin name] blockchain explorer" will usually find one.

17044: <p>With <a href="https://blockchain.info/tobtc?currency=USD&amp;value=10" rel="nofollow">https://blockchain.info/tobtc?currency=USD&amp;value=10</a></p>

<p>I find that $10 = 0.01724138 BTC</p>

<p>And with <a href="https://data.bter.com/api/1/ticker/drk_btc" rel="nofollow">https://data.bter.com/api/1/ticker/drk_btc</a></p>

<p>I find that 1 DRK = 0.017669 BTC</p>

<p>How can I get from those two bits of info $10 worth of DRK?</p>

<p>Also, Is there an equivalent site like blockchain.info for each coin?</p>
 4276: <p>Though TimS's method works, I always prefer to find the conversion factor. In this case, you want to know DRK per USD, or how much DRK will 1 USD buy.</p>

<ol>
<li><p>Simplify your BTC/USD factor</p>

<blockquote>
<pre><code>0.01724138 BTC      .00172414 BTC    
--------------   =  -------------  
    10 USD              1 USD
</code></pre>
</blockquote></li>
<li><p>Set up the conversion factor you are targeting. In this case, we want DRK on top and USD on bottom</p>

<blockquote>
<pre><code>.00172414 BTC          1 DRK
-------------   x   -------------  
    1 USD           .01766900 BTC
</code></pre>
</blockquote></li>
<li><p>The BTC unit cancels out and we are left with:</p>

<blockquote>
<pre><code>.00172414       1 DRK       .0975798290 DRK
---------   x   -----   =   ---------------
.01766900       1 USD           1 USD
</code></pre>
</blockquote></li>
</ol>

<p>So 1 USD will buy you about a tenth of 1 DRK. Notice I added two extra decimals than the typical 8; this will account for up to three digit values that you want to multiply the factor by, because you loose decimals with every 10th.</p>

<p>Now you have the conversion factor and you can multiply it by any USD amount (that I assume you are considering investing) to get exactly how much DRK that will work out to. In this case, you said 10 USD so</p>

<blockquote>
<pre><code>.0975798290 * 10 = .9757982900
</code></pre>
</blockquote>

<p>We round that off to eight decimals and you get your amount. 10 USD will buy .97579829 DRK.</p>
 12034: <p>Simple multiplication will find that:</p>

<pre><code>0.01724138 BTC / 10 USD * 
1 DRK / 0.017669 BTC =
0.01724138/10/0.017669 DRK/USD ~=
0.975798 DRK / 10 USD
</code></pre>

<p>10 USD is just under 1 DRK.</p>

<blockquote>
  <p>Also, Is there an equivalent site like blockchain.info for each coin?</p>
</blockquote>

<p>Most altcoins do have one or more <a href="https://en.bitcoin.it/wiki/Block_chain_browser" rel="nofollow">block chain browser</a>/explorer sites. Searching for "[altcoin name] blockchain explorer" will usually find one.</p>
