## 232. Math Puzzle $9 / 84$

A motorcycle battery ( $6 \mathrm{~V}$ ) is discharged through a lamp $6 \mathrm{~V} / 0.5 \mathrm{~W}$. The lamp burns for 48 hours.

How many Ah was the battery charged if we assume that the discharge current remains constant?
The discharge current is $I=\frac{0.5 \mathrm{~W}}{6 \mathrm{~V}}=\frac{1}{12} \mathrm{~A}$.

If we assume that it remains constant during continuous discharge, the battery previously had $48 \cdot \frac{1}{12} \mathrm{Ah}=4 \mathrm{Ah}$ charged.