Question

A rectangular field is masured 390m by210m. How long will it take for a girl to go to times round the field, if she walks at the rate of 2m/s​

Answer 1

Answer:

20 minutes

Step-by-step explanation:

Length of rectangular field = 390 m

Breadth of rectangular field = 210 m

Perimeter = 2(l+b) = 2(390+210) = 2(600) m = 1200 m

Distance covered = 2×1200 m = 2400 m

Speed of girl = 2 m/s

Time taken = (2400 ÷ 2) s = 1200 s = 20 minutes

Answer 2

Given:

• A rectangular field is masured 390m by210m.
• a girl walks at the rate of 2m/s

To Find:

• How long will it take for a girl to go two times round the field

Solution:

$\sf \underline{★According \: to \: the \: question : }$

First let's find the perimeter of the field:

$\sf: \implies { \blue{perimeter}} = 2(l + b) \: \: \: \: \: \: \: \: \: \: \\ \\ \sf: \implies { \blue{perimeter}} = 2(390 + 210) \\ \\ \sf: \implies { \blue{perimeter}} = 2 \times 600 \: \: \: \: \: \: \: \: \: \\ \\ \sf: \implies { \blue{perimeter}} = 1200m \: \: \: \: \: \: \: \: \: \: \:$

As the girl should go two times round the field:

$\sf: \implies { \red{distance \: covered \: by \: her : }} \: 1200 \times 2 \\ \\ \sf: \implies { \red{distance \: covered \: by \: her : }} \: 2400m \: \: \: \:$

_____________________

$\sf: \implies { \orange{time}} = \frac{distance}{speed} \\ \\ \sf: \implies { \orange{time}} = \cancel\frac{2400}{2}sec \: \\ \\ \sf: \implies { \orange{time}} = 1200 \: sec$

$\blue{ \underline{ \boxed{ \pink{ \sf{ \therefore \:time \: taken \: by \: the \: girl =1200sec/20min }}}}}$

hope this helps.!!