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Question 6:, , Rita goes 20 km towards east from a point A to the point B. From B, she moves 30 km, towards west along the same road. If the distance towards east is represented by a, positive integer then, how will you represent the distance travelled towards west? By, which integer will you represent her final position from A?, , West B East, «+ >, , , , Answer:, , Since the distance towards east is represented by a positive integer, the distance, travelled towards west will be represented by a negative integer., , Distance travelled in east direction = 20 km, Distance travelled in west direction = -30 km, Distance travelled from A = 20 + (-30) = -10 km, , Therefore, we will represent the distance travelled by Rita from point A by a negative, integer, i.e., -10 km (i.e., Rita is now in west direction)., , Question 7:, , In a magic square each row, column and diagonal have the same sum. Check which of, the following is a magic square., , 5 -1 -4 1 -10 0, -5 -2 7 -4 -3 -2, 0 3 -3 -6 4 =f., (i) (ii), Answer:, , It can be observed that in square (i), every row and column add up to give 0. However,, the sum of one of its diagonals is not 0., , As-4-2=-60,, Therefore, (i) is not a magic square., , Similarly, in square (ii), each row, column, and diagonal add up to give -9. Therefore, (ii), is a magic square.