Respuesta :
Answer:
- 78125 dimes
Step-by-step explanation:
The payment for sessions makes a series
- 5 dimes, 5*5 = 25 dimes, 25*5 = 125 dimes, ...
This series is GP with the first term of 5 and common ratio of 5.
The nth term would be
- [tex]t_n=5*5^{n-1}[/tex]
Use the equation above and find the 7th term
- [tex]t_7=5*5^6 = 5^7 = 78125[/tex]
Answer:
[tex]a_7=5(5)^{6}[/tex]
78125 dimes
Step-by-step explanation:
The given scenario can be modeled as a geometric sequence.
A geometric sequence has a common ratio (multiplier) between each term, so each term is multiplied by the same number.
General form of a geometric sequence:
[tex]a_n=ar^{n-1}[/tex]
where:
- n is the nth term
- a is the first term
- r is the common ratio
Given:
- The friend will pays 5 dimes the first time you help him.
Therefore, a = 5
Given:
- The friend multiplies your payment by 5 for each study session.
Therefore, r = 5
Substitute these values into the formula to create an equation for the nth term.
[tex]\implies a_n=5(5)^{n-1}[/tex]
To find the number of dimes he will pay after 7 sessions, simply substitute n = 7 into the found equation:
[tex]\implies a_7=5(5)^{7-1}[/tex]
[tex]\implies a_7=5(5)^{6}[/tex]
[tex]\implies a_7=5 \cdot 15625[/tex]
[tex]\implies a_7=78125[/tex]
Therefore, the friend will pay 78125 dimes after the 7th study session.