ACT HelperACT Helper
Browse ACT math questions by topic
Practice
Practice timed math sections
Pricing | → Login
    See all search results
  1. Home
  2. A09 Math
  3. Question 12
  • 2018 April(A09) Math Question 12

    Sequences and Patterns

    - Arithmetic Sequences

    Choice G

    $$a_1=10 $$ $$d=2 $$ $$a_n=10+2(n-1)=2n+8 $$ $$S_n=\frac {a_1+a_n}{2}\cdot n=\frac {10+2n+8}{2}\cdot n=220 $$ $$n=11$$

    Skills you are tested for:

    Was this explanation helpful?
    Thanks for your feedback! ❤️
  • Comments

    To leave a comment,
    or Log in
TwitterFacebookDiscordEmail

© 2023 ACT Helper, an Ease.so product. All rights reserved.