A person buys some pens and pencils. The pen costs Tk.7 ech and pencil costs Tk.3 each. If he spends exactly Tk.81 and buys the maximum numbers of pen possible under these conditions, what is the ratio of pen to pencil?

প্রশ্নঃ A person buys some pens and pencils. The pen costs Tk.7 ech and pencil costs Tk.3 each. If he spends exactly Tk.81 and buys the maximum numbers of pen possible under these conditions, what is the ratio of pen to pencil?