Answer:
You will receive 262,144 pennies after completing the 9th job.
Explanation:
Given:
Payment for 1st job = 4 pennies
The payment is quadrupled after this for each job completed.
Payment after 2 jobs = 16 pennies
Payments after 3 jobs = 64 pennies
To find the number of pennies you will receive after the 9th job.
Solution:
Let 
 represent the payment after 1st job.
 represent the payment after 1st job. 



The sequence is in geometric sequence with common ratio = 4
The n
 term of a geometric sequence is given as:
 term of a geometric sequence is given as:

For the sequence:



For the sequence we need the payment after 9th job. So, we are finding 
 .
.




Thus, you will receive 262,144 pennies after completing the 9th job.