Answer : A. 5265
There was a mistake in the options. It has been corrected now.
Solution
Biggest 4 digit number formed from these digits = 8743
Smallest 4 digit number formed from these digits = 3478
Difference = 8743 - 3478 = 5265
Option A 84 m is the right answer.
Solution : The area of square is 144 m as given. Hence, the side of square is 12 m. The length of one smaller square in the shaded square is 6 m.
Hence the length of the rectangle is 6+6+6+6 =24
the breadth of rectangle is 6+6+6=18
The perimetre of rectangle is 2(l+b) = 2 (24+18) = 2*42 = 84 m
Ans is 84. Area of the square = 12 x 12 = 144 which means 12 is the length of two sides of the square, therefore each side will be 6 and there are 14 sides. Hence the perimeter is 14 x 6 = 84