Numeric Math choices are almost always listed from least to greatest. Use that order instead of testing every letter. Plugging in is in plugging in answers.
One comparison, then a direction
Start in the middle so one result tells you which way to walk, in start in the middle of the choices. If C is already too large, A and B are the only remaining candidates.
If a choice is not a number, order will not help. Move on, in the two-pass method. The section is 45 questions in 50 minutes, in how long the ACT is.
The bottom line
Least to greatest. Test a middle value, then follow the inequality.
Start practicing
Start with a free diagnostic, then drill your weak spots with 15-question quizzes and track how you're doing across Reading, English, and Math. Compare plans whenever you're ready to go further.
This article offers general ACT prep guidance. The ACT can change from year to year, including its format, scoring, policies, test dates, and fees, so always confirm the latest details on the official ACT website at act.org before you make decisions. ACT® is a registered trademark of ACT, Inc. thirty-six is not affiliated with, endorsed by, or sponsored by ACT.