Final answer:
The new price is GH¢1.38 after a 15% increase from the original price of GH¢1.20.
Step-by-step explanation:
To find the new price, we need to calculate the 15% increase on the original price of GH¢1.20.
15% of GH¢1.20 is (15/100) * GH¢1.20 = GH¢0.18.
Adding this increase to the original price, the new price becomes GH¢1.20 + GH¢0.18 = GH¢1.38.
Therefore, the correct answer is GH¢1.38.