Room A stores basketsballs and Room B stores soccer balls. Mr Li took 1/4 of the basketballs and placed them in Room B. He took 1/4 of the soccer balls and placed them in Room A.
2 soccer balls were loaned out of Room A and 4 basketballs were loaned out of Room B.
The ratio of the number of basketballs to soccer balls in Room A became 6 : 1.
The ratio of the number of basketballs to soccer balls in Room B became 4 : 9.
How many soccer balls were there in Room B at first?
