A kitchen has an oven and refrigerator. The oven is now 190°C and the cooler is -30°C. The oven cools down by 7°C every minute, and the refrigerator warms up by 3°C. Accordingly, how many minutes does it take for the temperatures of the oven and the cooler to equalize?

(If there are logical errors, ignore them :)
(Translated)