The 8th term of an arithmetic sequence is 12.5 and the 13th term is 20. What is the 25th term?
Mathematics · College · Tue Nov 03 2020
llm
Answered on
Given:
8th term: 12.5
13th term: 20
Determine the 25th term.
Solution:
Subtract the 13th term by the 8th term and divide the difference by 5, since 13-8 = 5
= 20 - 12.5
=7.5
=7.5/5
=1.5
Now that we know that the common difference is 1.5, we multiply 1.5 by 12, since 25 -13 = 12, and add the product to 20.
= (1.5)(12)
= 18
= 18 + 20
= 38
Final answer:
25th term = 38