There were 30 cans of soda in the fridge. 60% were Coke and the rest were Pepsi. Noah drank a few cans of Coke and now 75% of the soda cans in the fridge are Pepsi. How many cans of Coke did Noah drink?
If 60% of them were coke and the rest were pepsi, then 3/5 of 30 is 18 and 2/5 is 12, so at the beginning, there are 18 cans of coke and 12 cans of pepsi.
Since the percentage after Noak drank the coke of pepsi is 75%, that means it is a 3:1 ratio, pepsi:coke. Bringing this into the ratio of the 12 cans of pepsi, that would mean there would be 4 cans of coke left. 18 - 4 = 14, so Noak drank 14 cans of coke.