Question

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?

Answer 1

`20` minutes

Explanation:

Its given that the rectangular filed is `150m` long and `50m` 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)`
where, `l` = length of the rectangle and, `w` = width of the rectangle.
The multiplication factor of `2` in the equation above is to denote the `2` lengths and `2` widths that each rectangle has.

Now, the perimeter of the field = `2(150+50)` = `400m`
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`