You can ask Wolfram|Alpha to solve any problem where people (or letters) have some common objects (like apples) and then gain, lose, or swap these objects. Wolfram|Alpha knows to ignore any irrelevant information and shows a calculation and illustration to help you understand how the numbers in the problem were used to find the solution.
Avogadro’s number is about twice the number of stars in the observable universe.
Now you can find the ideal curvature for a curve with Wolfram|Alpha!