P6 math question math teacher gave me

Each orange takes up 4/3 as much volume as each pear

Thus....each orange can be considered as 4/3 of a pear

Therefore....if there already 28 pears in the basket, it could hold 12 more pears

But.......we could only have 9 more oranges in the basket because 9 (4/3)pears = 12 pears

Another way to look at it:

the basket is  28/40 full of pears.....thus it is  12/40 EMPTY      12/40 (30 oranges) = 9 oranges can still fit in it.