Can you solve the clues to find out who's who on the friendship graph?
Can you find a way to connect each house to the utilities without any pipes crossing?
How can you decide if a graph is traversable?
Can you find the missing constants from these not-quite-so-obvious definite integrals?
Can you find a polynomial function whose first derivative is equal to the function?
Can you explain what is going on in these puzzling number tricks?
Can you describe the route followed by the arrows?