Good night :). Sleep tight!
The sum of 3/5 and 1/10 is 7/10.
The last answer is the correct one.
If it does not make sense ask for clarification.
936936 is the perimeter and perimeter of a square is 4 times the length of one of the sides. therefore, you divide 936936 by 4 and get your answer, which is 234234.