You can find the common denominator which in this case is 12 and multiply both 1/3 and 2/3 by 4 to get 4/12 and 8/12 and you can clearly see this way the 4/12=1/3<7/12<8/12=2/3
or this question you should know that: 1/3 = (1*4)/(3*4) = 4/12 and 2/3 = (2*4)/(3*4) = 8/12 so you can see that 7/12 is greater than 4/12 which is 1/3 and less than 8/12 which is 2/3 :)))) i hope this is helpful have a nice day
