1/3 is a percentage of a number
The best way to think of 1/3 is half of half. You have 90. Half of 90 is 45(half of 80 is 40 and half of 10 is 5, just add the 40+5)
okay so half of 90 is 45. What's half of 45? Half of 40 is 20 and half of 5 is 2.5, so it's 22.5.
3 times 30 will give you 90. 3 and 1/3 are different