Question

A canal of width 1 m is constructed all along inside the field which is 24 m long and 15 m wide. Find (i) the area of the canal (ii) the cost of constructing the canal at the rate of ₹ 12 per sq.m.

Answer 1

Length of the field L = 24 m

Width (Breadth) of the field B = 15 m

(i) Area of the field = L × B sq.units

= 24 × 15 m² 

= 360 m² 

(ii) Width of the canal (W) = 1 m

Length of the field without canal (l) = L – 2(W)

= 24 – 2(1) m

= 24 – 2 m

= 22 m

Width of the field without canal (b) = B – 2W

= 15 – 2(1) m

= 15 – 2 m

= 13 m

Area of the field without canal = l × b sq.units

= 22 × 13 m² 

= 286 m²

Area of the canal = 360 – 286 = 74 m²

Cost of constructing 1 m² canal = ₹ 12

Cost of the constructing 74 m² canal = ₹ 12 × 74

= ₹ 888