UPSC Civil Services 2021 Prelims General Studies Paper II

From January 1, 2021, the price of petrol (in Rupees per litre) on m‌th ‌ day of the year is 80+0.1m, where m=1,2,3,...,100 and thereafter remains constant. On the other hand, the price of diesel (in Rupees per litre) on n‌th ‌ day of 2021 is 69+0.15n for any n. On which date in the year 2021 are the prices of these two fuels equal?