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:
The total of the 15 tickets would be $240
Step-by-step explanation:
If you divide 48 and 3 you get 16 which is the cost for each ticket and then yuo multiply 16 by 15 and you get 240
There are a few definitions depending on your context ( which is not that great btw) but some possible definitions are - Congruent, Equivalent, Proportionate
The sequence is not geometric or arithmetic because there is no common difference or common ratio between each term.
Not a Geometric or Arithmetic Sequence