Lisa ran around a rectangular field 150 m long and 50 m wide at an average speed of 100 m/min. How long did she take to complete 5 rounds?

Lisa ran around a rectangular field 150 m long and 50 m wide at an average speed of 100 m/min. How long did she take to complete 5 rounds?

1 Answer
Dec 29, 2017

2020 minutes

Explanation:

Its given that the rectangular filed is 150m150m long and 50m50m wide.

To make one round of the field, Lisa will have to cover the entire perimeter of the field.

The perimeter of a rectangle = 2(l+w)2(l+w)
where, ll = length of the rectangle and, ww = width of the rectangle.
The multiplication factor of 22 in the equation above is to denote the 22 lengths and 22 widths that each rectangle has.

Now, the perimeter of the field = 2(150+50)2(150+50) = 400m400m
Lisa's average running speed = 100 m/min

So, time taken to cover 1 round of the field or 1 perimeter of the field = 400/100 = 4 minutes.

So, to cover 5 rounds or 5 perimeters, Lisa will take:
5xx4 minutes = 20 minutes