Area problems
- 1. if the side of a square be increased by 4 cms. The area increased by 60 sq. cms . The side of the square is?
Options- A. 12 cm
- B. 13 cm
- C. 14cm
- D. None of these Discuss
Correct Answer: None of these
Explanation:
Let each side = x cm
Then, (x + 4 )2 - x2 = 60
? x 2 + 8x + 16 - x2 = 60
? x = 5.5 cm
- 2. A veranda 40 meters long 15 meters broad is to paved with stones each measuring 6 dm by 5 dm. the number of stones required is?
Options- A. 1000
- B. 2000
- C. 3000
- D. None of these Discuss
Correct Answer: 2000
Explanation:
Length = (40 x 10 ) dm = 400 dm.
Breadth = (15 x 10 ) dm = 150 dm.
Area of veranda = (400 x 150 ) dm2
Area of one stone = (6 x 5 ) dm2
? Required number of stones = (400 x 150) /(6 x 5) = 2000
- 3. The length of a rectangular plot is twice of its width. If the length of a diagonal is 9?5 meters, the perimeter of the rectangular is?
Options- A. 27 m
- B. 54 m
- C. 81 m
- D. None of these Discuss
Correct Answer: 54 m
Explanation:
Let breadth = y meters,
Then, length = 2y meters
? Diagonal = ?y2 + (2y)2
= ?5y2 meters
So, ?5y2 = 9 ?5
? y= 9
Thus, breadth = 9 m and length = 18 m
? Perimeter = 2 (18 + 9) m = 54m.
- 4. The length and breadth of a playground are 36 m and 21 m respectively. Flagstaffs are required to be fixed on all along the boundary at a distance of 3 m apart. The number of flagstaffs will be?
Options- A. 37
- B. 38
- C. 39
- D. 40 Discuss
Correct Answer: 38
Explanation:
Perimeter = 2 x (36 + 21 ) m = 144 m
? Number of flagstaffs = 144 / 3 = 38
- 5. If the length of diagonal AC of a square ABCD is 5.2 cm then area of the square ABCD is?
Options- A. 15.12 sq.cm
- B. 13.52 sq.cm
- C. 12.62 sq.cm
- D. 10 sq.cm Discuss
Correct Answer: 13.52 sq.cm
Explanation:
Area = 1/2 x (Diagonal)2
= (1/2) x 5.2 x 5.2 cm2
= 13.52 cm2
- 6. The length of a rectangle is twice its breadth. If its length is decreased by 5 cm and the breadth is increased by 5 cm, the area of the rectangle is increased by 75 cm 2 . Therefore , the length of the rectangle is?
Options- A. 20 cm
- B. 30 cm
- C. 40 cm
- D. 50 cm Discuss
Correct Answer: 40 cm
Explanation:
Let breadth = b, length = 2b
? Area of rectangle = 2b x b
= 2b2
As per question.
? (2b - 5 ) (b + 5 ) = 2b2 + 75
? 5b = 75 + 25
? 5b = 100
? b = 100 / 5 = 20
Hence, length of the rectangle =2b
= 2 x 20
= 40 cm.
- 7. A park of 10 meters long and 8 meters broad. What is the length of the longest pole that can be placed in the park?
Options- A. 10 metres
- B. 12.8 metres
- C. 13.4 metres
- D. 18 metres Discuss
Correct Answer: 12.8 metres
Explanation:
Length of the longest pole = ? [(10)2 + (8)2] m
= ? 164 m
= 12.8 m
- 8. The ratio of the area of two square, one having and double its diagonal than the other is?
Options- A. 2:1
- B. 3:1
- C. 3:2
- D. 4:1 Discuss
Correct Answer: 4:1
Explanation:
Let the diagonal of one square be (2d) cm
Then, diagonal of another square = d cm
? Area of first square = [ 1/2 x (2d)2] cm2
Area of second square = (1/2 x d2) cm2
? Ratio of area = (2d)2/ d2
= 4/1 = 4: 1
- 9. If the diameters of a circle is increased by 100% . Its area is increased by?
Options- A. 100%
- B. 200%
- C. 300%
- D. 400% Discuss
Correct Answer: 300%
Explanation:
Original area = ?(d/2)2
= (?d2) / 4
New area = ?(2d/2)2
= ?d2
Increase in area = (?d2 - ?d2/4)
= 3?d2/4
? Required increase percent
= [(3?d2)/4 x 4/(?d2) x 100]%
= 300%
- 10. The ratio of the area of square of side a and equilateral triangle of side a is?
Options- A. 2 :1
- B. 2 : ?3
- C. 4 :3
- D. 4 : ?3 Discuss
Correct Answer: 4 :3
Explanation:
Ratio of area = a2/ ?(3/4) a2
= 4/?3 = 4:?3
More in Aptitude:
Programming
Copyright ©CuriousTab. All rights reserved.