Answer:
The 15th term is 160
Step-by-step explanation:
The details are not clear. So, I will make the following assumptions
[tex]d = 10[/tex] ---- common difference
[tex]a_1 = 20[/tex] ---- first term
Required
The 15th term
This is calculated as:
[tex]a_{n} = a + (n - 1) * d[/tex]
Substitute 15 for n
[tex]a_{15} = a + (15 - 1) * d[/tex]
[tex]a_{15} = a + 14 * d[/tex]
Substitute values for d and a
[tex]a_{15} = 20 + 14 * 10[/tex]
[tex]a_{15} = 20 + 140[/tex]
[tex]a_{15} = 160[/tex]
