Answer:
17:21
Explanation:
The ratio 68:84 in its simpliest form is;
68:84 (Since it can divided by 2 perfectly);
34:42 (We also divide this by 2 )
17:21
17:21 is the final answer and it can be divide any further. Since 17 is a prime number, it can't be divided and also 21 can be divided by 3 but 17 can't be divided by 3 so we leave the final answer like that.