Answer: 26 weeks
Step-by-step explanation:
This is an example of an arithmetic sequence.
The first term = 3.5
common difference = 0.5
Using the formula for calculating the nth term of an arithmetic sequence :
[tex]t_{n}[/tex] = a + (n - 1 ) d
Therefore :
16.5 = 3.5 + ( n - 1 ) x 0.5
16. 5 = 3.5 + 0.5n - 0.5
16.5 = 3 + 0.5n
16.5 - 3 = 0.5n
13.5 = 0.5n
n = 13.5/0.5
n = 27
Therefore , it will take the cat (n-1) weeks to weigh 16.5 ounce, which will be 27 - 1 = 26
check:
3.5 + 26 ( 0.5)
= 3.5 + 13
= 16.5
