Answer:
25
Step-by-step explanation:
The n th term of an AP is
[tex]a_{n}[/tex] = a₁ + (n- 1)d
where a₁ is the first term and d the common difference
Here d = 5, then
a₁₈ = a₁ + 17d = a₁ + 85
a₁₃ = a₁ + 12d = a₁ + 60
Thus
a₁₈ - a₁₃
= a₁ + 85 - a₁ - 60
= 25
