Jonah makes hamburgers at Hamburger Heaven. At lunchtime, he assembled a total of 50 hamburgers. He put onions on 24 of those burgers and tomatoes on 30 of the burgers. If 22 had both onions and tomatoes, how many sandwiches had neither onions nor tomatoes? I think the answer's 10, but I suck at these type of questions.
<p><a class="tumblr_blog" href="http://qa.pwnthesat.com/post/93042446581/jonah-makes-hamburgers-at-hamburger-heaven-at">pwnthesat</a>:</p>
<blockquote><p>Make a Venn diagram:</p>
<p><span data-src="https://31.media.tumblr.com/da57fc7d452cafaa4cbcc798a960688c/tumblr_inline_n9de1wxCDU1qio24w.png" class="image-deferred"></span></p>
<p>The info in black is pulled straight from the question. The info in red comes from subtracting:</p>
<ul><li><span>24 – 22 = 2 gives you the number of burgers that had only onions, </span></li>
<li><span>30 – 22 = 8 gives you the number of burgers with only tomatoes. </span></li>
<li><span>50 – 2 – 22 – 8 = 18 gives you the number of burgers with neither ingredient.</span></li>