Question

9. The area of a square field is 60025 m². A man cycles along its boundary at 18 km/hr. In
how much time will he return at the starting point ?
10. The cost of levelling and turfing a square lawn at Rs 2.50 per mº is Rs 13322.50. Find
the cost of fencing it at Rs 5 per metre.
11. Find the greatest number of three digits which is a perfect square.
12. Find the smallest number which must be added to 2300 so that it becomes a perfect
square.
Orn​

Answer 1

Answer:

9.He will return to starting point in 196 seconds.

Step-by-step explanation:

Area of square field = 60025 sq.m.

Area of square = Side ^2Side

2

So, 60025=Side ^260025=Side

2

\sqrt{60025}=Side

60025

=Side

245=Side245=Side

Since we are given that he cycles along the boundary of field

So, Perimeter of square field =4 \times Side4×Side

Perimeter of square field =4 \times 2454×245

Perimeter of square field =980 m980m

So, Total distance = 980 m

Speed = 18 km/h =18 \times \frac{5}{18} =5 m/s18×

18

5

=5m/s

Time =\frac{Distance}{Speed}Time=

Speed

Distance

Time =\frac{980}{5}Time=

5

980

Time =196Time=196

Hence he will return to starting point in 196 seconds.

10.The cost of fencing is Rs.1460.

Step-by-step explanation:

Given : The cost of leveling a square lawn at Rs . 2.50 per square meter is Rs. 13322.50.

To find : The cost of fencing it at the rate of Rs .5 per meter?

Solution :

The cost of leveling a square lawn is Rs.13322.50

\text{Cost}=\text{Area}\times \text{Rate}Cost=Area×Rate

13322.50=\text{Area}\times 2.5013322.50=Area×2.50

\text{Area}=\frac{13322.50}{2.50}Area=

2.50

13322.50

\text{Area}=5329Area=5329

Area of the square lawn,

A=side^2A=side

2

5329=side^25329=side

2

(73)^2=side^2(73)

2

=side

2

Side of the lawn = 73 m

Now, Perimeter of the square lawn is

P=4\times sideP=4×side

P=4\times 73P=4×73

P=292mP=292m

The cost of fencing it at the rate of Rs .5 per meter

The cost of fencing is

C=292\times 5=1460C=292×5=1460

Therefore, The cost of fencing is Rs.1460.

11.961 is the greatest number of three digit which is perfect cube.

12.use long division method

48

4 2300

4 16

88-700

8 704

-4

23000 is 4 (704-700) less than 48 square.

Hence 4 must be added to 2300 yo get a perfect square

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