Correct Answer: 16:5

Explanation:

Area of a square SxS = 1024 => S = 32 cm
Length of the rectangle = 32x2 cm = 64 cm
Breadth of the rectangle = 32 - 12 = 20 cm
Required ratio = 64 : 20 = 16 : 5

Correct Answer: Rs. 345.15

Explanation:

area of the plot = 120m x 60m = 7200 sq.m
area of plot excluding gravel = 117m x 57m = 6669 sq.m
area of gravel = 7200 sq.m - 6669 sq.m = 531 sq.m
cost of building it = 531 sq.m x 65 ps = 34515 ps
In Rs. = 34515/100 = Rs. 345.15.

Correct Answer: 153600

Explanation:

Let length = 3x metres and breadth = 2x metres.

Then, 2(3x + 2x) = 1600 or x = 160.

Length = 480 m and Breadth = 320 m.Area = (480 x 320) sq.m = 153600 sq.m

Correct Answer: 13

Explanation:

Area =  1 2 * d i a g o n a l 1 * 1 2 d i a g o n a l 2 =  1 2 * 24 * 10 sq.cm  

 

1 2 * d a i g o n a l 1 = 1 2 * 24 = 12 c m 

 

1 2 * d i a g o n a l 2 = 1 2 * 10 = 5 c m 

side of a rhombus = (12)² + (5)² = 169      => AB = 13cm

Correct Answer: 31.68kmph

Explanation:

In this type of question, we will first calculate the distance covered in given time.

 

Distance covered will be : Number of revolutions x Circumference 

 

So we will be having distance and time, from which we can calculate the speed. 

 

Radius of wheel = 70 / 2 = 35 cm

 

Distance covered in 40 revolutions will be  40 * c i r c u m f e r e n e = 40 * 2 ?r = 40 * 2 * 22 7 * 35 = 8800 cm = 88 m

 

Distance covered in 1 sec  =  88 10 = 8 . 8 m / s = 8 . 8 * 18 5 k m / h r = 31 . 68 k m / h r

 

 

 

 

 

 

 

 

Correct Answer: 18

Explanation:

a =  1 2 × 15 × 12 = 90 sq.cm  

b = 2a =  1 2 × 20 × h  

h= 18cm

Correct Answer: 84m

Explanation:

let inner radius be r meters. 

$$\begin{gathered} 2 ?r = 440 ? r = 440 × 7 44 = 70 m \\ radius of outer circle = 70 + 14 m \end{gathered}$$  

 

Therefore, Radius of outer circle = 70 + 14 = 84m

Correct Answer: 115.395 sq cm

Explanation:

Because each vertice of the square is the center of a circle
(1/4) part of the total area of each circle inside of the square.
(3/4) part of the total area of each circle outside of the square.
Thus total area outside the square is 4 3 4 × 22 7 × 3 . 5 × 3 . 5 = 115.3955 sq cm.

Correct Answer: Rs. 3900

Explanation:

Area = (l + b ? d) d

= (80 + 60 ? 10)10

=> 1300 sq.mts

=> 1300 x 3 = Rs.3900

Correct Answer: 360sq metre

Explanation:

Let the breadth of rectangle be x m.

Then, the length of rectangle = (x+ 6) m

Perimeter of rectangle = 2 (x+x+ 6) m

Therefore, 2 (x+x+ 6) = 84 m

4x+ 12 = 84

4x= 84 ?12
4x = 72/4 = 18
Therefore, length of rectangle = 18 + 6 = 24 m = height of triangle

Diagonal of rectangle = ?(324+576) = 30 m = base of triangle

Therefore, are of triangle =1/2× base × height =1/2× 24 × 30 = 360 sq. m