Molarity of solution = 0.08 M
Molarity shows the number of moles of solute in every 1 liter of solution or mmol in each ml of solution
[tex]\tt M=\dfrac{n}{V}[/tex]
Where
M = Molarity
n = number of moles of solute
V = Volume of solution
[tex]\tt mol=0.2~M\times 100~ml=20~mlmol=0.02~mol[/tex]
Volume of solution = 100 ml + 150 ml = 250 ml
[tex]\tt M=\dfrac{0.02~mol}{0.250~L}=0.08[/tex]