Ethereum SAT

Test your knowledge of Ethereum and its underlying technology!

About four years ago, Olaf Carlson-Wee of Coinbase released a reddit post looking for more support staff to join the company. He created a Bitcoin test with some semi-advanced questions to gauge their knowledge (you can still take it here). Looking back in retrospect, the test seems relatively straightforward, compared to how the field has progressed as a whole. I decided to make an Ethereum SAT* to test your knowledge of Ethereum internals, in spirit of the Bitcoin test. Enjoy, and happy quizzing!


  • What do the terms "wei", "finney", and "szabo" refer to in Ethereum?
  • Name two solutions to running out of gas in a smart contract.
  • Ethereum recently hard forked, but no new coins were created. What gives?
  • What's the approximate cost to store one gigabyte of data on the Ethereum blockchain? (without solutions like Filecoin or Swarm)
  • What does maintaining state enable in Ethereum, and what fundamental data structure modification from Bitcoin allows for that?
  • What is geth's fast sync and what makes it fast?
  • What are the differences between partially light, fully light, and archive nodes?
  • What is LLL, Solidity, and Serpent, and how does it relate to the EVM? Which is the most popular of the three?
  • What's the total supply of Ethereum? What is the "ice age"?
  • What is a colored coin and how does it relate to Ethereum tokens?
  • Briefly describe how you would write a naming service in a smart contract (think something like DNS).
  • What happens when a smart contract is broadcast to the network? Who runs the smart contract?
  • What happens when multisig control of a DAO splits? (alternatively, what happens when a token forks?)
  • What happens to a DAO when the base Ethereum protocol has a network split (resulting in two different coins)?
  • What is economic finality in Casper, and what does it achieve/solve compared to Nakamoto consensus?
  • What's the difference between Casper, the Friendly Finality Gadget and Casper, Correct-by-Construction?
  • What is a slashing condition?
  • What are long-range attacks and the nothing-at-stake problem, and how are they subverted?
  • Where do the slashed Ether deposits of byzantine nodes go when not following the Casper protocol?
  • What is a "layer two" system, and how is security guaranteed without a blockchain?
  • Lightning Network is a project involving payment-specific state channels. How does this work generalize to Plasma?
  • Ethereum recently added support for zero-knowledge proofs. How does it solve the trusted setup criticism posed in ZCash? Does it?
  • What is ASIC resistance and how does Ethereum's Proof-of-Work algorithm accomplish it?
  • Describe Ethereum's "holy trinity" initiative and its three components.

Ethereum is full of lots of exciting developments (it's a living science project!), so it was only natural to create an Ethereum version of the "Bitcoin Test". Given the depth of the Ethereum Project, I wasn't able to cover everything, unfortunately. If you have an interesting question about Ethereum, comment it down below! Answers can be viewed here.

Thanks to Dillon Chen for for giving me feedback on earlier versions of this post.

*Note: "SAT" is a registered trademark of the College Board, to whom I have no relation. Please don't sue me.

Have any questions or comments? Feel free to comment down below or shoot me a message on twitter @niraj.