Su Lin and Tina made some necklaces over 2 days. On Monday, Su Lin made 17 more necklaces than Tina. On Tuesday, Su Lin made 30 necklaces and Tina made 11 necklaces. At the end of the 2 days, Tina made $\frac{1}{4}$ of the total number of necklaces. How many necklaces did Su Lin make?

1. Find the difference in the number of necklaces made by Su Lin and Tina on Tuesday.

Difference on Tuesday = $30 - 11 = 19$

2. Find the total difference in the number of necklaces made over the 2 days.

Total difference = $17 + 19 = 36$
Su Lin made $36$ more necklaces than Tina in total.

3. Express the number of necklaces each made in units based on the given fraction.

Tina made $\frac{1}{4}$ of the total.
This means Tina made $1$ unit and the total is $4$ units.
Su Lin made: $4 - 1 = 3$ units.
Difference in units = $3 - 1 = 2$ units.

4. Find the value of 1 unit.

$2 \text{ units} = 36$
$1 \text{ unit} = 36 \div 2 = 18$

5. Calculate the total number of necklaces Su Lin made.

Su Lin made $3$ units.
$3 \times 18 = 54$