The sides of a rectangular field are in the ratio 3 : 4. If the area of the field is 8748 sq. m, the cost of fencing the field @ 25 paise per metre is  Choose the correct choice
A) rs . 55.50 B) rs . 67.50 C) rs . 86.50 D) rs . 94.50 E) none of these

Rationale: "solution let length = ( 3 x ) metres and breadth = ( 4 x ) metres . then , 3 x × 4 x = 8748 ⇔ 12 x 2 = 8748 ⇔ x 2 = 729 ⇔ x = 27 . so , length = 81 m and breadth = 108 m . perimeter = [ 2 ( 81 + 108 ) ] m = 378 m . ∴ cost of fencing = rs . ( 0.25 × 378 ) = rs . 94.50 . answer d"
Answer: D