33 1/3% dari 60 sama dengan 66 2/3% dari...? Ada yang tau caranya ga kak?

33 1/3 % = 100/3 x 1/100 = 1/3
66 2/3 % = 200/3 x 1/100 = 2/3

1/3 x 60 = 2/3 x a
20 = 2/3 x a
a = 20 : 2/3
a = 20 x 3/2
a = 30