Formula:
C1V1=C2V2
Meaning: (Required concentration)(Required Volume)=(Given Concentration)(Unknown volume to be diluted)
(0.2)(10)=(1.0)(V2)
V2= 2 cm^3.
There is actually less of a formula approach and more of a mathematical one. If you have math in your AS/A Level too, follow this. Otherwise, just remember the formula in it's real meaning.
0.2 moles of solute ----> 10 cm3 of solution
1.0 mole of solute ----> x cm3 of solution
(1.0)(x) = (0.2)(10) {this is an inversely proportional relationship}
x = 2 cm3.