Answer:
From the countries point of view with the weaker currency, their goods are relatively cheaper to other countries, and other countries goods are relatively more expensive to this country (Say Country A) as they have a weaker currency.
From the point of view of Country B, with a stable currency, Country A's goods are relatively cheaper because they have a weaker currency.
Due to this scenarios, Country B will export less to Country A than import because Country B will be buying more of Country A's product as it is relatively cheaper. It will export less to Country A because Country B's products are relatively more expensive to Country A due to their weak currency.
