user31281: From https://www.sps.ed.ac.uk/sites/default/files/pictures/ekja03/Mining25.pdf page 10:

The bitcoin system is therefore designed to ensure that it takes around ten minutes on average before any miner anywhere manages to discover a nonce, or pair of nonces, that generates a hash with enough zeros. /…/

What is a pair of nonces and how does a pair of nonces solve a block?

user13866: 
What is a pair of nonces [...]

I guess they refer to nonce and extranonce.

[...] and how does a pair of nonces solve a block?

Talk of "solving" a block doesn't make much sense. They just mean that miners find values for the data in a block that result in the hash of the block being a number no bigger than the current network target number. Those values include nonce, extranonce and others.

31281: <p>From <a href="https://www.sps.ed.ac.uk/sites/default/files/pictures/ekja03/Mining25.pdf" rel="nofollow noreferrer">https://www.sps.ed.ac.uk/sites/default/files/pictures/ekja03/Mining25.pdf</a> page 10:</p>
<blockquote>
<p>The bitcoin system is therefore designed to ensure that it takes around ten minutes on average before any miner anywhere manages to discover a nonce, or pair of nonces, that generates a hash with enough zeros. /…/</p>
</blockquote>
<p>What is a pair of nonces and how does a pair of nonces solve a block?</p>
 13866: <blockquote>
<p><strong>What is a pair of nonces [...]</strong></p>
</blockquote>
<p>I guess they refer to <a href="https://bitcoin.stackexchange.com/questions/tagged/nonce">nonce</a> and <a href="https://bitcoin.stackexchange.com/search?q=extranonce">extranonce</a>.</p>
<blockquote>
<p><strong>[...] and how does a pair of nonces solve a block?</strong></p>
</blockquote>
<p>Talk of &quot;solving&quot; a block doesn't make much sense. They just mean that miners find values for the data in a block that result in the hash of the block being a number no bigger than the current network target number. Those values include nonce, extranonce and others.</p>
