Ethereum Ecosystem, EVM, and Role in Financial Markets BFC Practice Questions (Page 5)

Questions 21–25

1. 21application · medium

   A company wants to issue a token that represents a loyalty point system. The points should be transferable between users and should be interchangeable (1 point = 1 point). Which Ethereum standard is most appropriate?

   • AERC-20
   • BERC-721
   • CERC-1400
   • DERC-1155
   Reveal Solution Discussion Select an answer first
2. 22application · medium

   A company is launching a loyalty rewards program where customers earn points that can be redeemed for discounts. The points are fungible and can be transferred between customers. The company also wants to issue limited-edition collectible badges that are unique. Which token standard should they use for the loyalty points?

   • AERC-1155, because it can handle both points and badges in one contract.
   • BA custom standard, because existing standards do not support transferable points.
   • CERC-721, because it allows for unique badges, but it is not suitable for fungible points.
   • DERC-20, because loyalty points are fungible and need to be transferable.
   Reveal Solution Discussion Select an answer first
4. 23application · medium

   A developer is building a decentralized voting system for a shareholder meeting. The system must ensure that each shareholder can vote only once and that votes are transparent and auditable. Which approach best meets these requirements?

   • AUse an ERC-721 token to represent each vote, but this does not prevent double voting.
   • BUse a centralized database to collect votes and then publish the results on Ethereum.
   • CUse a smart contract that records each shareholder's vote on-chain, with a mapping to track whether they have voted.
   • DUse a multi-signature wallet to require multiple approvals for each vote.
   Reveal Solution Discussion Select an answer first
5. 24application · medium

   A developer is deploying a smart contract to Ethereum mainnet. The developer wants to ensure that the contract's bytecode is publicly verifiable and that the source code is available for audit. What should the developer do?

   • ADeploy the contract to a private blockchain
   • BKeep the source code private to protect intellectual property
   • CPublish the source code and verify the contract on a block explorer
   • DUse a proxy contract to hide the implementation
   Reveal Solution Discussion Select an answer first
6. 25expert · hard

   A smart contract developer is designing a decentralized exchange (DEX) that must be resistant to front-running attacks. The developer is considering using a commit-reveal scheme, where users submit a hash of their order and later reveal the details. However, this increases the number of transactions and gas costs. Which approach best balances security and cost?

   • ARely on the network's Proof of Stake consensus to prevent front-running.
   • BUse a centralized order book off-chain and settle on-chain only the final trades.
   • CUse a batch auction mechanism, where orders are collected and executed at a single clearing price, reducing the opportunity for front-running.
   • DUse a commit-reveal scheme for all orders, accepting the higher gas costs to ensure security.
   Reveal Solution Discussion Select an answer first