Answer:
Henrik buys 40 collectible cards per month and Kharif sells 20 cards from his collection of 180 each month. To find out when Henrik will have more cards than Kharif, we need to calculate the number of months it will take for Henrik to have more cards than Kharif.
We can calculate this by subtracting the number of cards Kharif sells each month from the total number of cards he has. So, after one month, Kharif will have 180-20 = 160 cards, and Henrik will have 40 cards. After two months, Kharif will have 160-20 = 140 cards, and Henrik will have 40+40 = 80 cards. After three months, Kharif will have 140-20 = 120 cards, and Henrik will have 80+40 = 120 cards.
Therefore, it will take three months for Henrik to have more cards than Kharif. After three months, Henrik will have 120 cards and Kharif will have 120 cards. At this point, Henrik will have more cards than Kharif.
In conclusion, it will take three months for Henrik to have more cards than Kharif. After three months, Henrik will have 120 cards and Kharif will have 120 cards, and Henrik will have more cards than Kharif.