Question

The area of a square field is 18496 sq metre. A girl cycles along its boundary at 12 km per hour. In how much time will she return at the starting time.

Answer 1

Area = 18496 m^2

Side = √Area units [Since, Area = (Side)^2]
= √18496 m
= 136 m

Perimeter = (4×Side) units
= (4×136) m
= 544 m

Speed = 12 km/h
= (12000/3600) m/s

Time = Distance/Speed
= 544/12000/3600
= 544×360/12000
= 163.2 seconds

Answer 2

The girl will return at the starting point in 2min 18sec.

Given:

The area of a square field is 18496 $m^{2}$.

A girl cycles along its boundary at 12 km/h.

To Find:

We have to find that in how much time will she return at the starting point.

Solution:

Area of the square field = 18496 $m^{2}$

∴Side of the square field = √Area units [Since, Area = $side^{2}$]

                                         = √18496 m

                                         = 136 m

Perimeter  of a square field= (4×Side) units

                                            = (4×136) m

                                            = 544 m

Speed of the girl with cycle = 12 km/h

                                              = (12000÷3600) m/s

                                              = $\frac{10}{3}$ gain, we know that, Time = $\frac{Distance}{Speed}$

                                             = $\frac{544}{\frac{10}{3} }$  s

                                             = $544*\frac{3}{10}$ s

                                             = $\frac{\frac{1632}{10} }{60}$ min

                                             = 2 min 18sec

Hence, she will return at the starting point in 2min 18sec.                                            

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