Answer
This is not the correct method, because it does not produce a 0.500M solution.
Work Step by Step
Volume after dilution: 30 ml + 270 ml = 300 ml
1. Find the concentration after the dilution:
$C_1 * V_1 = C_2 * V_2$
$1.50 * 30.0= C_2 *300$
$45.0 = C_2 *300$
$C_2 =0.150 M$
