A rectangular ground has length (21) m more than its breadth and area (550) square m. What is its length?

Correct answer: (46) m

Direct answer: The length is 46 m, so option D is correct. Let the breadth be x metres. The length is 21 m more, so it is x+21. Area equals length × breadth, hence x(x+21)=550. Expanding gives x^2+21x−550=0. Factoring: (x−25)(x+46)=0, so x=25 or x=−46. A length cannot be negative, so breadth = 25 m. Therefore length = 25+21 = 46 m. Option D is correct. Option A, 22 m, does not make the product 550 with a breadth 1 m; it is not the calculated length. Option B, 25 m, is the breadth, not the length. Option C, 40 m, does not produce the required dimensions and difference. The negative algebraic root is rejected because physical measurements are positive. Memory cue: first find the smaller dimension, then add the stated difference to obtain the length.