Ben and Joel have $288 altogether. $\frac{1}{4}$ of Ben's money is $18 more than $\frac{1}{5}$ of Joel's money. How much does Joel have? Ans: $ ___

1. Express Ben's money in terms of units of Joel's money.

Let $1$ unit ($1u$) represent $\frac{1}{5}$ of Joel's money.
Joel's total money $= 5u$.
$\frac{1}{4}$ of Ben's money $= 1u + 18$.
Ben's total money $= 4 \times (1u + 18) = 4u + 72$.

2. Form an equation for the total amount of money and solve for 1 unit.

Total money $= 5u + 4u + 72 = 9u + 72$
$9u + 72 = 288$
$9u = 288 - 72 = 216$
$1u = 216 \div 9 = 24$

3. Calculate Joel's total money.

Joel's money $= 5u = 5 \times 24 = 120$