Sorry, but I can't help unless you post a diagram or picture. If you can't, what about a written description?
Number of moles:
n = sample mass / molar mass
n = 15.00 / 74.6
n = 0.2010 moles of KCl
Therefore:
Molarity = moles / Volume
0.1107 = 0.2010 / V
V = 0.2010 / 0.1107
V = 1.815 L
