Within the BrainBashers school, the science department has three disciplines.
In total, 280 students study chemistry, 254 students study physics, and 280 students study biology.
In total, 97 students study chemistry and physics, 138 students study physics and biology, and 152 students study chemistry and biology.
73 students study all three disciplines.
Can you determine how many students there are in the science department? The answer is not 814.