To find equivalent ratios just factor the same number to both numerator and denominator. I will make the ratios simple by multiplying 2/2 and 3/3 to the originals. To check, set as fraction and cross multiply and you should have the same number. I will show you how to check by doing it to the first ratio.
8:5 16:10 24:15
Check:
8/5 = 16/10
(8)(10)=(5)(16)
80=80
8/5=24/15
(8)(15)=(5)(24)
120=120
4:19 8:38 12:57
6:23 12:46 18:69