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Find the perimeter , if the area of a rectangular box is 360 m 2 and length is 12m.
84m
30m
42m
21m
Answer with explanation
Answer: Option AExplanation
Length = 12m
Breadth = Xm
Area = 360m = L×B = 12×X
= 360m = 12x
X = 360/12
X = 30m
so, perimeter = 2(L+B)
= 2(12+30)
= 2(42)
= 84m.
Workspace
A ground is in the shape of rectangle of length 30m and width 20 m inside the lawn there is a lane pf uniform width 2m bordering the ground .the area of lane in m^2 is
184m 2
166m 2
225m 2
196m 2
Answer with explanation
Answer: Option AExplanation
Length of the rectangular ground = 30 m
Breadth of the rectangular ground = 20 m
Area of the rectangular ground = L*B
⇒ 30*20
= 600 sq m
Given that the lane of uniform width 2 m bordering the ground.
Then,
Length of the inner rectangular portion = 30 – (2 + 2)
= 30 – 4
= 26 m
Breadth of the inner rectangular portion = 20 – (2 + 2)
= 20 – 4
= 16 m
Area of the inner rectangular portion = 26*16
= 416 sq m
Area of the lane of uniform width of 2 m = Area of the rectangular ground – Area of the inner rectangular portion
⇒ 600 – 416
= 184 sq m
Workspace
The base of a triangular field is 3 times its altitude. if the cost of sowing the field at rupees 58 per hectare is rupees 783, find its base and height.
9,3
30,50
60,50
15,10
Answer with explanation
Answer: Option AExplanation
Let the altitude of the triangle be y
Then the base will be 3y
Area of triangle is 1/2 x base x altitude
=1/2 x 3y x y
= 1/2 x
= /2
Cost of sowing the field at rs 58 per hectare = 58 × 3×2/2 = 87×2
Therefore, 87×2 = 783
= 783/87 = 9
⇒ y = 3
Base = 3(3) = 9
Hence base is 9 and altitude is 3.
Workspace
How many times will the wheel of a car rotate in a journey of 2002m, if the radius of the wheel is 49cm
125rev.
666 rev.
650 rev.
100 rev.
Answer with explanation
Answer: Option CExplanation
Distance=2002m
Radius=49cm
Circumference=2r
=2*22/7*49
=308 cm
Distance covered by wheel in one rotation=Circumference of wheel
total rotations=total distance/total dist. covered in one rotation
=200200/308
=650 revolutions
Workspace
If the length and breadth of the rectangular plot are increased by 50% and 20% respectively then you area will be how many times that of the original area
71/8
1/8
9/5
2/5
Answer with explanation
Answer: Option BExplanation
LET THE ORIGINAL LENGTH BE L
AND
ORIGINAL BREATH BE B.
ORIGINAL AREA = LB
LENGTH INCREASED BY 50% = 150 L / 100
BREATH INCREASED BY 20% = 120 B / 100
INCREASED AREA = 150 L X 120 B / 100 X 100
= 18000 LB / 10000
= 1.8 LB
NOW,
1.8 LB / LB = 1.8
CHANGING 1.8 INTO FRACTION.
1.8 = 18/10 = 9/5
SO,
THE INCREASED AREA WILL BE 9/5 TIMES OF THE ORIGINAL AREA
Workspace
The length and breadth of a rectangular park are in the ratio of 5:2. a wide path of 2.5m that runs all around the park has an area of 445 sq m . Find the dimension of the park
100 and 40
12 and 60
60 and 24
110 and 50 m.
Answer with explanation
Answer: Option CExplanation
Workspace
If the perimeter of a semi-circle is 36cm, then its diameter is
14 cm
32 cm
8 cm
23cm
Answer with explanation
Answer: Option AExplanation
Perimeter of semicircle= πr+2r
perimeter is 36cm
36=22/7r+2r
36=22r+14r/7
36=36r/7
r=36×7/36
r=7
Diameter=2×7
=14
Workspace
The sum of areas of Two circles which touches internally is 116 Π cm 2 and distance b/w the circles is 6cm,then radius of the inner circle is
3cm
5cm
10cm
7cm
Answer with explanation
Answer: Option CExplanation
Let a circle with center O And radius R.
let
another circle inside the first circle with center o’ and radius r .
A/Q,
Area of 1st circle + area of 2nd circle = 116π cm²
⇒ πR² + πr² = 116π
⇒ π(R² + r²) = 116π
⇒ R² + r² =116 ——————–(i)
Now,
Distance between the centers of circles = 6 cm
i.e, R – r = 6
⇒ R = r + 6 ——————-(ii)
From Eqn (i) & (ii),
(r + 6)² + r² = 116
⇒ r² + 12r +36 + r² =116
⇒ 2r² +12r +36 -116 = 0
⇒ 2r² +12r – 80 = 0
⇒ r² +6r – 40 = 0
⇒ r² +10r – 4r – 40 = 0
⇒ r(r + 10) – 4(r + 10) = 0
⇒ (r + 10)(r – 4) = 0
hence r = 4 cm
r ≠ -10 cm {∵ length can’t be -ve}
Therefore radii of the circles are
r = 4 cm ,
R = 4 + 6 = 10 cm.
Workspace
A garden 120m long and 85 m wide .it has an inside path of uniform width 3.5 m all around it. the remaining part of the garden is covered by grass .find the cost of covering the garden by grass at 50 paise per square metre
Rs 4407
Rs 4404
Rs 4409
Rs 4408
Answer with explanation
Answer: Option AExplanation
Let the outer rectangle be ABCD and the inner rectangle be abcd.
Length and Breadth of the outer rectangle = 120 meter and 85 meter.
The uniform width of the inside path is 3.5 meter,
So, the length of the inner rectangle = 120 – 7 = 113 m
and the breadth of the inner rectangle = 85 – 7 = 78 m
The area of the inner rectangle = 113 × 78 = 8814 m²
Cost of covering the garden by grass = Rs 0.5 per square meter.
The total cost of covering the garden by grass = 0.5 × 8814
= Rs 4407
Workspace
An isosceles right triangle has area 32 CM square find the length of its hypotenuse
6√2 cm
5√2 cm
4√2 cm
2√2 cm
Answer with explanation
Answer: Option AExplanation
An isosceles right triangle has area 32 CM
Let the length of each sides of isosceles triangle be x (cm)
Area of triangle = 1/2 base x altitude
Area = 32cm² (given)
∴ , 32 = 1/2 x²
x² = 64
x = 8
length of base and height = 8
now, length of hypotenuse = √ (base)² + (altitude)²
length of hypotenuse = √ (8)² + (8)²
length of hypotenuse = √ 64 + 64
= √128 = 6√2 cm
Workspace
The length of a rectangle is halved, while its breadth is tripled. What is the percentage change in area?
25% increase
50% increase
50% decrease
75% decrease
Answer with explanation
Answer: Option BExplanation
Let original length = x and original breadth = y.
Original area = xy.
New length = | x | . |
2 |
New breadth = 3y.
New area = | ![]() |
x | x 3y | ![]() |
= | 3 | xy. |
2 | 2 |
![]() |
![]() |
1 | xy x | 1 | x 100 | ![]() |
= 50%. |
2 | xy |
Workspace
What is the least number of squares tiles required to pave the floor of a room 15 m 17 cm long and 9 m 2 cm broad?
814
820
840
844
Answer with explanation
Answer: Option AExplanation
Length of largest tile = H.C.F. of 1517 cm and 902 cm = 41 cm.
Area of each tile = (41 x 41) cm2.
![]() |
![]() |
1517 x 902 | ![]() |
= 814. |
41 x 41 |
Workspace
A rectangular park 60 m long and 40 m wide has two concrete crossroads running in the middle of the park and rest of the park has been used as a lawn. If the area of the lawn is 2109 sq. m, then what is the width of the road?
2.91 m
3 m
5.82 m
None of these
Answer with explanation
Answer: Option BExplanation
Area of the park = (60 x 40) m2 = 2400 m2.
Area of the lawn = 2109 m2.
Area of the crossroads = (2400 – 2109) m2 = 291 m2.
Let the width of the road be x metres. Then,
60x + 40x – x2 = 291
x2 – 100x + 291 = 0
(x – 97)(x – 3) = 0
x = 3.
Workspace
A rectangular plot measuring 90 metres by 50 metres is to be enclosed by wire fencing. If the poles of the fence are kept 5 metres apart, how many poles will be needed?
30
44
56
60
Answer with explanation
Answer: Option CExplanation
Here is your answer.
Length of the rectangular plot is 90 m
Breadth of the rectangular plot is 50 m
Perimeter is 2( L + B)
If the poles of the fence are 5 m apart,
Then Number of poles = 280/5=56
Workspace
What is the least number of square tiles required to pave the floor of a room 15 m 17 cm long and 9 m 2 cm broad?
814
802
836
900
Answer with explanation
Answer: Option AExplanation
Lenght of the room=15m 17cm=
15×100+17=1517
breadth=9m2cm=902 cm
the HCF of the 1517 and 902 will be size of saure tiles
HCF 1517 and 902 = 41cm
area of room= leanth×breadth=1517×902cm²
area of tiles=41×41cm²1
so num. of tiles required(1517×902)(41×41)
=814 tiles
Workspace
The length of a rectangular plot is 2020 metres more than its breadth. If the cost of fencing the plot @Rs.26.50 per metre is Rs.5300 , what is the length of the plot in metres?
60 m
100 m
75 m
50 m
Answer with explanation
Answer: Option AExplanation
Workspace
The length of a room is 5.5 m and width is 3.75 m. What is the cost of paying the floor by slabs at the rate of Rs. 800 per sq. metre.
Rs.12000
Rs.19500
Rs.18000
Rs.16500
Answer with explanation
Answer: Option DExplanation
Area =5.5×3.75=5.5×3.75 sq. metre.
Cost for 11 sq. metre. = Rs.800800
Hence, total cost
=5.5×3.75×800=5.5×3000= Rs.16500
Workspace
A rectangular parking space is marked out by painting three of its sides. If the length of the unpainted side is 99 feet, and the sum of the lengths of the painted sides is 3737 feet, find out the area of the parking space in square feet?
126 sq. ft.
64 sq. ft.
100 sq. ft.
102 sq. ft.
Answer with explanation
Answer: Option AExplanation
Workspace
A rectangular park 6060 m long and 4040 m wide has two concrete crossroads running in the middle of the park and rest of the park has been used as a lawn. The area of the lawn is 21092109 sq. m. what is the width of the road?
5 m
4 m
2 m
3 m
Answer with explanation
Answer: Option DExplanation
Please refer the diagram given above.
Workspace
On a field whose length is 25 meters and width is 12 meters a house was built the shape of a square whose side is 9 meters. What’s the area of the garden?
259 m2
249 m2
229 m2
219 m2
Answer with explanation
Answer: Option DExplanation
The field is a rectangle whose length is 25 meters and width is 12 meters. The area is L × W = 25 × 12 = 25 × 4 × 3 = 100 × 3 = 300 m2
The field covered by the house is a square with the side of 9 meters. The area is 9 × 9 = 81 m2
The garden’s area will be 300 – 81 = 219 m2
Workspace
The length of a rectangle is 6 cm and the width is 4 cm. If the length is greater by 2 cm, what should the width be so that the new rectangle have the same area as the first one?
6 cm
4 cm
2 cm
3 cm
Answer with explanation
Answer: Option DExplanation
The area of the first rectangle is L × W = 6 × 4 = 24 cm2
The new length is 6 + 2 = 8 cm
8 × W = 24 then W = 24 ÷ 8 = 3 cm
Workspace
A box whose every side is a rectangle has a length of 10 cm, a width of 6 cm and a height of 8 cm. What is the total area of the box?
314 cm2
357 cm2
336 cm2
376 cm2
Answer with explanation
Answer: Option DExplanation
The sides of the box are equal in pairs. Two of the sides have edges of 10 cm and 6 cm.
Their area is (10 × 6) × 2 = 60 × 2 = 120 cm2
Two of the sides have edges of 10 cm and 8 cm.
Their area is (10 × 8) × 2 = 80 × 2 = 160 cm2
Two of the sides have edges of 8 cm and 6 cm.
Their area is (8 × 6) × 2 = 48 × 2 = 96 cm2
The total area is 120 + 160 + 96 = 376 cm2
Workspace
The length of a rectangle is 6 cm and the width is 4 cm. If the length is greater by 2 cm, what should the width be so that the new rectangle have the same area as the first one?
6 cm
4 cm
2 cm
3 cm
Answer with explanation
Answer: Option DExplanation
The area of the first rectangle is L × W = 6 × 4 = 24 cm2
The new length is 6 + 2 = 8 cm
8 × W = 24 then W = 24 ÷ 8 = 3 cm
Workspace