Look at the units of time . . .
A company manufactures two products, A and B, using two machines I and II.
To make a unit of product A requires 6 minutes on Machine I and 5 minutes on Machine II.
To make a unit of product B requires 9 minutes on machine I and 4 minutes on machine II.
There are 5 hours (300 minutes) of machine time available in each work shift on machine I
and 3 hours (180 minutes) on machine II.