Aptitude - Questions & Answers

Area Calculation - Online Quiz

Quiz

Following quiz provides Multiple Choice Questions (MCQs) related to Area Calculation. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Q 1 - The length of a rectangular plot is 9/2 times that of its broadness. On the off chance that the region of the plot is 200 square meters, then what is the length?

Answer : D

Explanation

Let the breadth be x meters. Then, length =9x/2 meters.
∴ X*9x/2= 200 ⇒x²= 400/9 ⇒x= 20/3
∴ Length = (9/2*20/3) m = 30m

Q 2 - The aggregate expense of deck a room at rs.8.50 per square meter is Rs. 510. In the event that the length of the room is 8m, its expansiveness is:

Answer : A

Explanation

Area = total cost/rate =(510/8.50)m²= (510*2/17)m²= 60m²
Area =60m², Length= 8m
Breadth =Area/ Length = 60/8m =7.5 m

Q 3 - If the length of the rectangle is expanded by 20% and its expansiveness is diminished by 20%, then its zone:

Answer : B

Explanation

Let, length = x mtr. And breadth = y mtr. Then, area =(xy) m²
New length = (120/100*x) m = 6x/5 m, new breadth= (80/100*y) m
= 4y/5 m
New area = (6x/5 *4y/5) m²= (24/25xy) m²
Decrease in area = (xy- 24/25xy) m²
Decrease % = (xy/25*1/xy*100) %= 4%

Q 4 - The expense of developing a square field at the rate of Rs 160 for every hectare is Rs. 1440. The Cost of putting a wall around it at Rs.7.50 per meter is:

Answer : A

Explanation

Area of the square field = 1440/160 hectare = 9 hectare.
= (9*10000) m²= 90000m²
∴ Side of the square is = √90000= 300 m
∴ Perimeter = (4*300) m = 1200m
Cost of fencing = rs. (1200*15/2) = Rs. 9000

Q 5 - The territory of the four dividers of the room is 168m². The broadness and Length of the room is 8m and 6m. The length of the room is:

Answer : C

Explanation

2(L+8)*6= 168 ⇒L+8= 168/12= 14 ⇒L= (14-8) = 6m

Q 6 - Each side of an equilateral triangle measures 2√3cm.The length of its altitude is:

Answer : C

Explanation

Each side=  2√3
1/2 * base *altitude= √3/4* (2√3)² = √3/4 *12 = 3√3
⇒ 1/2 *2 √3* altitude= 3√3⇒altitude= 3cm

Q 7 - The sides of a triangular board are 13m, 14m and 15m. The cost of Painting it at rs. 8.75 per m² are:

Answer : B

Explanation

s= 1/2 (13+14+15) =21, (s-a)= 8 , (s-b)= 7 and (s-c) 6
Area to be painted = √21*8*7*6 m² =84 m²
Cost of painting = rs. (84* 8.75)= rs. 735

Q 8 - A circle is recorded in a square. An equilateral triangle of side

Answer : C

Explanation

Radius  of circumcircle of the triangle = a/√ 3= 4√ 3/√ 3=4cm
Side of the square = (2*4) =8cm
Diagonal of the square = √ (8)²+ (8)²= √ 64+64 =√ 128 =√ 2*64
= 8√ 2 cm

Q 9 - The region of a rhombus is 144cm². On the off chance that one of the diagonals is twofold the other, the lengths of the diagonals is:

Answer : B

Explanation

Let one diagonal be x cm. then, another diagonal = 2x cm
∴ 1/2 * x*2x= 144 ⇒x² =144 ⇒x= 12
Length of the diagonals is 12cm, 24 cm

Q 10 - The distinction between the radii of the smaller circle and the greater circle is 7cm and the contrast between the territories of the two circles is 1078 cm². Span of the littler circle is:

Answer : B

Explanation

Let the radii of the inner and outer circle be r and R cm.
Then, R-r= 7 and π (R²-r²) = 1078
∴ Π (R²-r²)/ (R-r) = 1078/7
⇒R+r = (1078/7*7/22) =49
On solving (R-r) =7 and (R+r) = 49, we get r= 21 cm

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