Explanation:
Let x=amount of sugar needed
Then 10x=amount of flour needed
Now we can set up an inequality:
40<= 11x <=50 divide each term by 11
40/11<=x<=50/11 now multiply each term by 10x (amount of sugar needed)
400/11 <= 10x <=500/11 or
36.36 <=10x <= 45.45
The possible weights of flour the baker can use is greater than or equal to 36.36 lb and less than or equal to 45.45 lb