In the given question, most of the information's are already provided. Using these information's the required answer can be easily found. Hideko has 3/5 yard of ribbon in total. He needs 3/10 yards of ribbon to tie 1 balloon. It has to be found, the number of balloons Hideko can tie with the total ribbon he has.
Let us assume that the number of balloons Hideko can tie = x
then
3/10 yard of ribbon is required to tie = 1 balloon
3/5 yard of ribbon can be used to tie = (10/3) * (3/5)
= 2
So Hideko can tie 2 balloons with the total ribbon he has.