Question

Lynne walks dogs every day to earn money. The fees she charges per month are 1 dog,$40;2 dogs,$37.25 each;3 dogs,$34.50 each;4 dogs,$31.75 each. A pet store wants her to walk 8 dogs if the pattern continues, how much will Lynne charge to walk each of the 8 dogs.

Answer 1

$ 59.25

Explanation:

The given rates form an AP (Arithmetic Progression).

Let the cost of walking 1 dog be taken as the first term

and,

cost of walking 2 dogs as second term,

we notice that the price per dog is decreasing by 2.75 $ each time the number of dogs is increasing by 1.

So, it's safe to say that

In the AP:

First term is $ 40

Common difference is $ 2.75

Finding the charge to walk each of the eight dogs is like finding the 8th term of the given Series.

Formula for n-th term of a depreciating AP in terms of common difference(d) and first term(a):

`\boxed{ \mathsf{a _(n) = a - (n - 1)d}}`

`\implies \mathsf{a _(8) = 40 - (8 - 1) * 2.75}`

`\implies \mathsf{a _(8) = 40 - 7 * 2.75}`

`\implies \mathsf{a _(8) = 40 - 19.25}`

`\implies \mathsf{a _(8) = \underline{20.75}}`

Answer:

Hence, the charge to walk each of the eight dogs is $ 20.75

Answer 2

The answer is $20.75

A dog: 40$

2: $37.25

3: $34.50

4: $31.75

5: $29

6: $26.25

7: $23.50

8: $ 20.75

Explanation:

Minus $2.75 is the pattern