Liquidity pools in Blockchain / Solidity - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a liquidity pool with two tokens.

Blockchain / Solidity

liquidityPool = {"tokenA": [1], "tokenB": 1000}

Drag options to blanks, or click blank then click option'

ANone

B"ETH"

C500

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string instead of a number for token amount.

The liquidity pool needs a numeric value for tokenA amount, so 500 is correct.

2fill in blank

medium

Complete the code to calculate the total liquidity in the pool.

Blockchain / Solidity

totalLiquidity = liquidityPool["tokenA"] + [1]

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AliquidityPool["tokenB"]

BliquidityPool.tokenB

C"tokenB"

DtokenB

Attempts:

3 left

💡 Hint

Common Mistakes

Using dot notation which doesn't work for dictionary keys.

Accessing tokenB amount from the dictionary requires the key in brackets and quotes.

3fill in blank

hard

Fix the error in the code to add liquidity correctly.

Blockchain / Solidity

def addLiquidity(pool, token, amount):
    pool[token] [1] amount
    return pool

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A+=

B-=

C*=

D/=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-=' which subtracts liquidity instead of adding.

To add liquidity, we increase the pool's token amount by the given amount using '+='.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that filters tokens with liquidity above 500.

Blockchain / Solidity

filteredPool = {token: pool[token] for token in pool if pool[token] [1] [2]

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A>

B500

C<

D1000

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' which filters tokens with less liquidity.

The comprehension keeps tokens with amounts greater than 500, so '>' and 500 are correct.

5fill in blank

hard

Fill all three blanks to create a dictionary of token prices where price is amount divided by 1000.

Blockchain / Solidity

tokenPrices = { [1]: pool[[2]] / [3] for [2] in pool }

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Atoken

C1000

Dtokens

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong variable names or missing division.

The dictionary comprehension uses 'token' as key and divides pool[token] by 1000 for price.