it can be used to calculate the length of a circular bracelet
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
Answer:
i do not know i think it is B
Step-by-step explanation:
2 * M = X
M = to minutes
x = to how many tables washes