Question

If Mary walks in a perfect circle around a perfectly circular pond, approximately how far has she walked if the diameter of the pond is measured to be 48 feet and she has taken 3 laps around the pond? A. 144 B. 150 C. 450 D. 1800

Answer 1

Answer: Option 'c' is correct.

Explanation:

Since we have given that

Diameter of the pond = 48 feet

Radius of the pond =
`(48)/(2)=24\ feet`

As we know the formula for "Circumference of circle":

So, Circumference of circle is given by

`2\pi r\\\\=2* (22)/(7)* 24\\\\=150.85\ feet\approx 150\ feet`

Number of laps around the lap = 3

So, Distance she walked in 3 laps is given by

`150.* 3\\\\=450\ feet`

Hence, Option 'c' is correct.

Answer 2

Answer: C. 450 feet

Explanation:

Given : Diameter of perfectly circular pond= 48 feet

We know that the circumference of circle is given by :-

`C=\pi d`

Then, the circumference of pond will be :-

`C=(3.14)(48)=150.72\ feet`

Since, she has taken 3 laps around the pond.

Then , the total distance covered by her =
`3* C`

`3*150.72=452.16\approx450` [Rounded to nearest tens.]

Hence, she walked 450 feet.