Respuesta :

part A. We are given that a hiker will increase the distance covered by 10% each day. Let "S" be the distance, then on the first day the distance is:

[tex]S_1[/tex]

On the second day, we must add 10% of the first day, we get:

[tex]S_1=S_1+\frac{10}{100}S_1[/tex]

Simplifying we get:

[tex]S_2=S_1+0.1S_1=1.1S_1[/tex]

On the third day, we add 10% of the second day, we get:

[tex]S_3=S_2+0.1S_2=1.1S_2=(1.1)(1.1)S_1=(1.1)^2S_1[/tex]

On the fourth day, we add 10% of the third day, we get:

[tex]S_4=S_3+0.1S_3=1.1S_3=(1.1)^3S_1[/tex]

If we continue this pattern and we set "n" as the number of days, then a formula for the distance after "n" days is:

[tex]S_n=(1.1)^{n-1}S_1[/tex]

Now, we are given that for n = 7 the distance is 75897, therefore, we substitute n = 7 in the formula:

[tex]S_7=(1.1)^{7-1}S_1[/tex]

Substituting the value of the distance:

[tex]75897=(1.1)^{7-1}S_1[/tex]

Now we can solve for S1, we do that by dividing both sides by 1.1 together with its

exponent:

[tex]\frac{75897}{(1.1)^{7-1}}=S_1[/tex]

Now we solve the operations:

[tex]\frac{75897}{(1.1)^6}=S_1[/tex]

Solving the operations:

[tex]42842=S_1[/tex]

Therefore, the distance the first day was 42842 miles.

part B. The formula for Sn is the given previously but we replace the known value of S1:

[tex]S_n=42842(1.1)^{n-1}[/tex]

Part C. To determine the distance after 10 days, we substitute the value n = 10 in the formula, we get:

[tex]S_{10}=42842(1.1)^{10-1}[/tex]

Solving the operations we get:

[tex]S_{10}=101019.19[/tex]

Therefore, the distance after 10 days is 101019.19 miles.