Answer
Find out the what fraction of the sandcastle did they build together .
To prove
Let us assume that the fraction of the sandcastle they build together be x .
As given
Than the equation becomes
L.C .M of (3,7) = 21
solving
Therefore the fraction of the sandcastle did they build together be
Hence proved
Constraints are simply the subjects of an objective function.
The inequality that represents the constraint is:
Represent the number of hats with x, and the number of scarves with y.
From the question, we have:
So, the equation of the total time spent is:
This time spent is not more than 20 hours.
So, the inequality is
Hence, the inequality that represents the constraint is:
Read more about constraints at: