Problem Analysis #11

Kimi K3 · Run 1

Correct
5.24s
841 toks

API · no tools. This is the prompt and response recorded for this attempt; a full solution may not have been returned.

Problem Statement

This is a Korean CSAT mathematics multiple-choice problem. Solve it and put only the correct choice symbol, one of ①, ②, ③, ④, ⑤, inside \boxed{}.

Problem 12 Let{a n}be a geometric sequence satisfying 2(a1 +a 4 +a 7) =a 4 +a 7 +a 10 = 6. Determine the value ofa 10. [4 points] ① 22 7 ② 24 7 ③ 26 7 ④ 30 7 ⑤ 32 7

Ground Truth
Recorded model response / solution
Reasoning Process

Let the common ratio be rr. Since a4=a1r3, a7=a1r6, a10=a1r9a_4=a_1r^3,\ a_7=a_1r^6,\ a_{10}=a_1r^9,

a4+a7+a10=r3(a1+a4+a7).a_4+a_7+a_{10}=r^3(a_1+a_4+a_7).

From 2(a1+a4+a7)=62(a_1+a_4+a_7)=6, we get a1+a4+a7=3a_1+a_4+a_7=3.
Then a4+a7+a10=6a_4+a_7+a_{10}=6 gives 3r3=63r^3=6, so r3=2r^3=2.

Now

a1(1+r3+r6)=a1(1+2+4)=7a1=3    a1=37.a_1(1+r^3+r^6)=a_1(1+2+4)=7a_1=3 \implies a_1=\frac37.

Thus

a10=a1r9=37(r3)3=378=247.a_{10}=a_1r^9=\frac37\cdot (r^3)^3=\frac37\cdot 8=\frac{24}{7}.

\boxed{②}

Final Model Output

Comparative Analysis (P11) (Average across runs)

Averages use reported measurements only. Missing usage is not treated as zero.

Avg Time Taken

Motif 3
20.3
Solar Pro 4
11.2
Kimi K3
9.1
K-EXAONE-2
1.4

Avg Token Usage

Solar Pro 4
887.0
Kimi K3
859.7
K-EXAONE-2
626.7
    CSAT 2026 · Problem 11 · Kimi K3 | EntropyMath