Question

How many moles of KNO3 are in 37.5 mL of .445 M KNO3?

Answer 1

Convert 50mL to liters by dividing it by 1000 to get your liters value which should be 0.05 L
Now your formula is .20 = x/0.05
Solve for x to get your mol value and you should get 0.01 mol

Answer 2

Volume =  37.5 mL in liters : 37.5 / 1000 = 0.0375 L

n = M x V

n = 0.445 x 0.0375

n = 0.0166875 moles of solute

Hope I helped!