A rectangular lawn of dimensions 80 m x 60 m has two roads each 10 m wide running in the middle of the lawn, one parallel to the length and the other parallel to the breadth. What is the cost of traveling the two roads at Rs.3 per sq m ?

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: 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: 18

Explanation:

a =  1 2 × 15 × 12 = 90 sq.cm  

b = 2a =  1 2 × 20 × h  

h= 18cm

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: 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: 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

Correct Answer: 1232

Correct Answer: 36m

Explanation:

Let the length of the rectangle be 3x and breadth be 1x
Given, perimeter = 96 m
2(l + b) = 96 (or) l + b = 48 (or) 3x + 1x = 48 (or) x = 12 m
Now, Length of the rectangle = 12 x 3 = 36 m

Correct Answer: ?265 cm

Explanation:

Correct Answer: 240