APTITUDE | ARITHMATICAL | AREA | PROBLEMS BASED ON AREA 2

DIRECTIONS : Problems based on area.

6.	A rectangular field is to be fenced on three sides leaving a side of 20 feet uncovered.If the area of the field is 680 sq.ft, how many feet of fencing will be required?
	A.  34	B.   40
	C.   68	D.   88

Solution

We have:L =20 ft and lb = 680 sq.ft b = 34ft Length of fencing = (l + 2b) = (20 + 68)ft = 88 ft.

7.	A large field of 700 hectares is divided into two parts. The difference of the areas of the two parts is one-fifth of the average o fthe two areas. What is the area of the smaller part in hectares?
	A.  225	B.  280
	C.  300	D.  385

Solution

Let the areas of the two parts be x and (700 - x)hectares = [x - (700 - x)] = 1 / 5 x [x + (700 - x)/ 2] = 2x - 700= 70 x = 385.

8.	2 metres broad pathway is to be constructed around a rectangular plot on the inside. The area of the plots is 96 sq.m. The rate of construction is Rs. 50 per square metre. Find the total cost of the construction?
	A.  Rs.2400	B.  Rs.4000
	C.  Data inadequate	D.  None of these

Solution

Given lb =96 Area of pathway = [(l-4)(b-4)-lb] = 16-4(l+b) Which cannot be determined. so, data is inadequate.

9.	A typist uses a sheet measuring 20cm by 30cm lengthwise.If a margin of 2 cm is left on each side and a 3 cm margin on top and bottom, then percent of the page used for typing is
	A.  40	B.  60
	C.  64	D.  72

Solution

Area of the sheet = (20 x 30 ) cm² = 600 cm² Area used for typing = [(20 - 4) x (30 - 6)] cm² =384 cm² Required percentage = (384 / 600 x 100)% =64 %.

10.	The length of a room is 5.5 m and width is 3.75 m. Find the cost of paying the floor by slabs at the rate of Rs. 800 per sq.metre.
	A.  Rs. 15,000	B.  Rs. 15,500
	C.  Rs. 15,600	D.  Rs. 16,500

Solution

Area of the floor = (5.5 x 3.75)m² = 20.635m ² Cost of paying = Rs. (800 x 20.625) =Rs.16500.