Answer:
50%, or 1/2 of its life remains.
Step-by-step explanation:
3 years is 36 months, by using 3 x 12(mo). If the watch battery is 18 months old, you can do 36 - 18 to get the remaining life, which would be 18. Then, to do the portioning, take this answer of 18 and divide it by 36 ( 18 / 36 ), which is approximately 0.5.
