The correct verb form here is "had stopped" because the action of the rain stopping is completed before the other action (leaving off coats) occurs. This requires the past perfect tense, which is used to show that one action was completed before another in the past.
Thus, the correct verb form is "had stopped," making the sentence: "The rain had stopped, so we left off our coats."
Arun’s present age in years is 40% of Barun’s. In another few years, Arun’s age will be half of Barun’s. By what percentage will Barun’s age increase during this period?