Hold the "3" for a moment and find the rational fraction that produces 0.24 with a bar over the 24:
0.24242424 ... = (first term) / (1 - common ratio)
= 0.24 / (1 - 0.01)
= 0.24 / (0.99) = 24/99 = 8/33
Then the rational number desired is 3 8/33; if you want to combine this result into one fraction, you'd get (99+8)/33, or 107/33. Check this yourself; the result is 3.24242424.....