<p>How does one tackle a question involving a venn diagram with 3 circles?</p>
<p>Also, what is a good place for checking out hard SAT math problems?</p>
<p>Hard Sat Problems → baron’s </p>
<p>And usually drawing the venn diagram helps me out. Think systems and surroundings (like thermochemistry) to quickly derive the necessary rules for the venn diagrams. A + B - both + none = Entire Sample Size</p>
<p>I also like to draw the problem out. Make sure to clearly label and use inclusion-exclusion properly.</p>
<p>Here’s an example problem I just made up:</p>
<p>A school has 3,000 students. Every student studied at least one of French, German, Italian. Exactly 50% of the students studied French, 45% studied German, and 35% studied Italian. 22% of the students studied exactly two languages. How many students studied all three languages?</p>