The sides of a rectangular field are in the ratio 3 : 4. If the area of the field is 10092 sq. m, the cost of fencing the field @ 25 paise per metre is	Choose the correct answer
A) rs . 55.50	B) rs . 67.50	C) rs . 86.50	D) rs . 101.50	E) none of these

Rationale: "solution let length = ( 3 x ) metres and breadth = ( 4 x ) metres . then , 3 x × 4 x = 10092 ⇔ 12 x 2 = 10092 ⇔ x 2 = 841 ⇔ x = 29 . so , length = 87 m and breadth = 116 m . perimeter = [ 2 ( 87 + 116 ) ] m = 406 m . ∴ cost of fencing = rs . ( 0.25 × 406 ) = rs . 101.50 . answer d"
Answer: D