when you do ratios, you can divide the main number by the sum of all the numbers in the ratio. this will give you "groups" or "units" that you divide the number into.
so first, we add 3+3+5=11
that means that the 1430 must be divided into 11 groups or units
1430/11=130
so each of this parts would have 130 kilograms in it.
then in a ratio 3:3:5 means 3 such parts, 3 such parts and 5 such parts
3*130=390
5*130=650
so the answer is
390:390:650