Solution:

It is given that

2: 3, 17: 21, 11: 14 and 5: 7

We can write it in fractions as

2/3, 17/21, 11/14, 5/7

Here the LCM of 3, 21, 14 and 7 is 42

By converting the ratio as equivalent

2/3 = (2 × 14)/ (3 × 14) = 28/42

17/21 = (17 × 2)/ (21 × 2) = 34/ 42

11/14 = (11 × 3)/ (14 × 3) = 33/42

5/7 = (5 × 6)/ (7 × 6) = 30/42

Now writing it in ascending order

28/42, 30/42, 33/42, 34/42

By further simplification

2/3, 5/7, 11/14, 17/21

So we get

2: 3, 5: 7, 11: 14 and 17: 21