A rectangular garden (60 m × 40 m) is surrounded by a road of width 2 m, the road is covered by tiles and the garden is fenced. If the total expenditure is Rs. 51600 and rate of fencing is Rs. 50 per metre, then the cost of covering 1 sq. m of road by tiles is :

Answer: Option C

Length of the fence :
= 2(60 + 40) m
= 200 m
Cost of fencing :
= Rs. (200 × 50)
= Rs. 10000
Area of the road :
= [(64 × 44) - (60 × 40)] m²
= (2816 - 2400) m²
= 416 m²
Let the cost of tiling the road be Rs. x per sq.m
∴ 416x + 10000 = 51600
⇒ 416x = 41600
⇒ x = Rs. 100