Answer:
9/30 and 20/30
Explanation:
You must find the least common denominator. To do this, list the multiples of each denominator, and find the lowest number that is the same between them.
10 = 10, 20, 30, 40, 50....
3 = 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33....
the lowest multiple that is the same between them is 30.