Well I don't know !
Let's get together and figure it out:
The product of ' A ' and ' B ' is (A B) .
If you decrease ' A ' by 25%, then ' A ' becomes ' 0.75 A ' .
If you decrease ' B ' by 50%, then ' B ' becomes ' 0.5 B ' .
Now their product is (0.75 A) x (0.5 B) .
In multiplication, the order of the factors doesn't matter.
So we car re-arrange the new product as
(0.75 x 0.5) x (A B) .
But (A B) is the original product, before we started
messing around with ' A ' and ' B '.
So the original product has become
(0.75 x 0.5) = 0.375 of itself .
The original product has been reduced by
(1 - 0.375) = 0.625 of itself.