380 Students Took the Same SAT Math Test. These Questions Beat Them.
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Sigma Prep
SAT Math Instructor · 10+ Years Experience
August 10, 2026·Updated September 7, 2026·6 min read
Prep companies love to talk about "the hardest SAT questions" based on feel. We do not have to guess. Our free practice test has now been completed by 380 students, which means every question on it has been answered by a couple hundred people under real conditions. We graded all 14,567 answers and ranked the questions by how often they actually get missed.
The floor is about 4%: the friendliest questions still trip a few people. The ceiling is 61%. Here is the top of the list and, more usefully, the patterns in it.
Key findings
Across 14,567 graded answers from 380 complete sittings of the same SAT Math practice test, per-question miss rates ran from 4% to 61%.
The most missed question, a surface-area problem about two combined rectangular prisms, was missed by 61% of students.
Free-response questions are about a quarter of the test but half of the ten most-missed questions.
The Five Most Missed
#1, missed by 61%. Two identical rectangular prisms combined into one solid, asking for surface area. The trap: gluing the prisms together makes two faces disappear, and adding the areas without subtracting them feels completely correct. A majority of students pick the answer that forgets the seam.
Area and Volume · Hardanswer C
Two identical rectangular prisms each have a height of 60 centimeters (cm) and a surface area of Kcm2. Each prism has a square base. When the two prisms are glued together along a square base, the resulting prism has a surface area of 1631Kcm2. What is the side length, in cm, of each square base?
#2, missed by 59%. A parabola with a given vertex that crosses the x-axis at a given point, asking which statement must be true. Pure vertex-form reasoning with no numbers to grind. If you know how symmetry pins the second intercept, it takes twenty seconds. If not, no amount of calculation rescues you.
Nonlinear functions · Hardanswer D
When the quadratic function f is graphed in the xy-plane, where y=f(x), its vertex is (−5,8). One of the x-intercepts of this graph is (−323,0). What is the other x-intercept of the graph?
#3, missed by 43%. A line, translated up two units, asked for its new x-intercept. This is the sleeper on the list. It is Algebra 1 content sitting in the first module, and it beats almost half of everyone. Students shift the intercept up instead of shifting the line and re-solving.
Linear equations in two variables · Hardanswer D
The table below gives the coordinates of three points on line h in the xy-plane.
x
y
2
22
5
34
7
42
Line k is the result of translating line h down 6 units. What is the x-intercept of line k?
#4, missed by 43%. A bookstore buys books wholesale, marks them up, then discounts them, asked for profit per book. Nothing here is hard. It is four small percent steps in a row, and one slip anywhere poisons the chain.
Percentages · Hardanswer 11.2
A craft store buys handmade candles for a purchase price of $8.00 each and then marks them each for sale at a consumer price that is 350% of the purchase price. After 3 months, any remaining candles not yet sold are marked at a discounted price that is 60% off the consumer price. What is the discounted price of each of the remaining candles, in dollars?
#5, missed by 36%. Two data sets, one built from the other, asking what happens to the mean. Statistics judgment with no formula to hide behind.
One-variable data · Hardanswer A
A data set consists of 31 different values. The mean and the median of the data set are both equal to 55. A new data set is created by adding 8 to each value that is greater than the median and subtracting 8 from each value that is less than the median. Which of the following measures of the new data set does NOT have the same value as that of the original data set?
Free-response is heavily overrepresented. Half of the ten most-missed questions are student-produced response, versus a quarter of the test. Remove the four multiple-choice options and the guardrails go with them: no answer to sanity-check against, no eliminating your way to a coin flip. If those questions spook you, they are less scary than they look, but the data says they are collecting real victims.
Module 2 dominates, but the module 1 entries are the scary ones. Eight of the top ten live in the harder second module, which is what you would expect. The two that live in module 1, the translated line and a system-of-inequalities point check, are the expensive ones, because module 1 performance decides which module 2 you even see.
Almost none of it is exotic math. A disappearing face, a shifted line, a chain of percents. These are recognition failures and process failures, not knowledge failures, which is the same conclusion we reached writing about why students miss questions they know how to do.
Under each of the five is a problem of the same type from the Sigma Prep practice banks, answer marked, with the video solution in the app. Same trap, different numbers, so trying it tells you whether the trap would have caught you.
Why We Are Not Showing the Solutions
Deliberately. This test is the diagnostic that builds your study plan, and a diagnostic only works on questions you have not rehearsed. Publish the answers and we would be quietly breaking the measurement for every future student, in exchange for a slightly more satisfying blog post. The trade is bad.
What we can tell you is that every one of these questions, and every other question on the test, comes with a full video solution after you have taken it. You see exactly what beat you while it is still fresh, then drill new versions of that exact type until it stops beating you.
See Where You Land
The test is free, it takes about 70 minutes under real timing, and the 61% question is waiting on the back half. If it gets you, you will be in good company, and you will know precisely what to fix. No card required. Start free today!
Common Questions
In 14,567 graded answers from 380 sittings of the same practice test, the most missed were a combined-prisms surface area question (61% missed), a parabola vertex reasoning question (59%), and a translated-line intercept question (43%). Most of the top ten sit in the harder second module, and half are free response.
No answer choices means no guardrails: nothing to sanity-check against and no way to eliminate down to a coin flip. Free response is about a quarter of SAT Math but half of the ten most-missed questions on our test.
Mostly no. The top of the list is a disappearing face on a glued solid, a line shifted up two units, and a chain of small percent steps. They are recognition and process failures, not exotic content.
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