• Difficulty - Medium
    Total Plays - 42
    Allowed Time - 10 sec
    Best time - 1.573

    Decentralized exchanges:

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    Explanation:
    Decentralized exchanges (DEXs) operate using smart contracts, which automatically execute trades without the need for intermediaries. This allows users to trade crypto directly from their wallets while maintaining control of their assets
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  • Difficulty - Medium
    Total Plays - 37
    Allowed Time - 10 sec
    Best time - 0.900

    Which opcode is deprecated but still callable?

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    Explanation:
    CALLCODE is deprecated due to unsafe context handling. It remains callable for backward compatibility but should never be used in new designs.
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  • Difficulty - Medium
    Total Plays - 20
    Allowed Time - 10 sec
    Best time - 1.062

    Why avoid multiple SSTOREs in a function?

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    Explanation:
    SSTORE is one of the most expensive operations and repeating it unnecessarily multiplies costs. Caching values into memory and writing once dramatically optimizes gas. This is foundational in gas-sensitive protocols.
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  • Difficulty - Medium
    Total Plays - 46
    Allowed Time - 10 sec
    Best time - 0.758

    Which hash function does Bitcoin use?

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    Explanation:
    Bitcoin uses the SHA-256 cryptographic hash function to secure transactions and link blocks in the blockchain. This algorithm produces a fixed 256-bit output, ensuring immutability and resistance to tampering. By using SHA-256, Bitcoin maintains trust, decentralization, and data integrity across the network
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  • Difficulty - Medium
    Total Plays - 38
    Allowed Time - 10 sec
    Best time - 0.959

    What does zk-SNARK stand for?

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    Explanation:
    zk-SNARKs are zero-knowledge proofs that improve blockchain privacy and scaling by verifying transactions without revealing sensitive data.
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  • Difficulty - Medium
    Total Plays - 31
    Allowed Time - 10 sec
    Best time - 1.388

    What is the purpose of the #[account] macro in Anchor?

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    Explanation:
    The #[account] macro in Anchor is used to define and validate account structures for Solana smart contracts. It simplifies account management and ensures data integrity.
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  • Difficulty - Medium
    Total Plays - 27
    Allowed Time - 10 sec
    Best time - 2.943

    Which Rust feature ensures type safety in blockchain data structures?

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    Explanation:
    Rust’s ownership model enforces strict rules on data access, preventing issues like double-spending in blockchain applications. It ensures compile-time safety for complex data structures.
    Leaderboard
  • Difficulty - Medium
    Total Plays - 30
    Allowed Time - 10 sec
    Best time - 1.424

    Which platform focuses on NFT-based games?

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    Explanation:
    Decentraland is a virtual world where users buy land and items as NFTs. It blends gaming and digital ownership.
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  • Difficulty - Medium
    Total Plays - 30
    Allowed Time - 10 sec
    Best time - 1.157

    MetaMask" is a

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    Explanation:
    MetaMask is a popular cryptocurrency wallet and browser extension that allows users to manage Ethereum-based assets and interact with decentralized applications (dApps). It securely stores private keys, enabling seamless transactions and access to Web3 platforms directly from the browser.
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  • Difficulty - Medium
    Total Plays - 47
    Allowed Time - 10 sec
    Best time - 1.211

    Blockchain Oracles provide

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    Explanation:
    A blockchain oracle is a service that connects a blockchain with real-world data from outside the network. It helps smart contracts get information like weather, prices, or sports scores so they can work properly.
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  • Difficulty - Medium
    Total Plays - 40
    Allowed Time - 10 sec
    Best time - 0.706

    What does Web3 rely on?

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    Explanation:
    Web3 uses blockchain to power trustless, decentralized applications.
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