The life of a watch battery is typically 3 years. If a watch’s battery is 18 months old what portion of its life remains?
The Correct Answer and Explanation is:
The watch battery’s life is typically 3 years, and we are given that the battery is 18 months old. To find out what portion of its life remains, we need to compare the remaining time with the total battery life.
Step 1: Convert the time into a consistent unit
Since the typical life of the battery is given in years, we first need to convert 18 months into years. There are 12 months in a year, so: 18 months=1812 years=1.5 years18 \, \text{months} = \frac{18}{12} \, \text{years} = 1.5 \, \text{years}18months=1218years=1.5years
Step 2: Subtract the used time from the total life
The total life of the battery is 3 years. Since 1.5 years have already passed, the remaining life is: 3 years−1.5 years=1.5 years3 \, \text{years} – 1.5 \, \text{years} = 1.5 \, \text{years}3years−1.5years=1.5years
Step 3: Find the portion of the life remaining
Now that we know 1.5 years remain, we can express this as a fraction of the total 3-year life. To do this, we divide the remaining time by the total battery life: 1.5 years3 years=12\frac{1.5 \, \text{years}}{3 \, \text{years}} = \frac{1}{2}3years1.5years=21
Conclusion:
The portion of the watch battery’s life that remains is 1/2 or 50%.
This means that half of the battery’s total life remains
