A rectangular grassy plot 100 m. by 70 m has a gravel path 2.5 m wide all round it on the inside. Find the cost of gravelling the path at 90 paise per sq. metre.	Choose the most appropriate option.
A) rs . 700	B) rs . 708.50	C) rs . 732.50	D) rs . 742.50	E) none of these

Rationale: "explanation : area of the plot = ( 100 x 70 ) m 2 = 7000 m 2 area of the plot excluding the path = [ ( 100 - 5 ) * ( 70 - 5 ) ] m 2 = 6175 m 2 . area of the path = ( 7000 - 6175 ) m 2 = 825 m 2 . cost of gravelling the path = rs . 825 * ( 90 / 100 ) = rs . 742.50 answer : option d"
Answer: D