Printed positive marks are preserved per question. The source uses different blank-answer and incorrect-answer rules by section, including an optional bonus penalty; the import does not reproduce that complete official scoring scheme.
Year 2026 assigned because the source does not state an exam year.
In the figure, $AB=18$, $BC=19$, $CA=17$. $D$ lies on $AB$, $E$ on $CA$, and $F$ on $DE$ such that $\angle DFB=\angle DBF$ and $\angle EFC=\angle ECF$. Find the perimeter of triangle $ADE$.
A palindrome is a positive integer whose digits read the same forwards and backwards; for example, 13431, 2552 and 77. How many palindromes lie between 2019 and 2562?
For a real number $x$, $[x]$ is the greatest integer not exceeding $x$ (the integer part). The fractional or decimal part is $\{x\}=x-[x]$, so $x=[x]+\{x\}$. Examples: $[3]=3$, $[6.25]=6$, $[-6.25]=-7$, $[22/7]=3$. The source lists: (1) $0<\{x\}<1$ for all real $x$; (2) $\{x\}=0$ exactly when $x$ is an integer; (3) $x-1<[x]\le x<[x]+1$; (4) $[n+x]=n+[x]$ for positive integer $n$ and real $x$; (5) $[-x]=-[x]-1$ if $x$ is not an integer, and $[-x]=-[x]$ if $x$ is an integer. Source correction: property (1) is printed as $0<\{x\}<1$ for all real $x$, contradicting both the definition and property (2) at integers. The correct bound is $0\le\{x\}<1$. The solution uses the definition and this corrected bound.
For a real number $x$, $[x]$ is the greatest integer not exceeding $x$ (the integer part). The fractional or decimal part is $\{x\}=x-[x]$, so $x=[x]+\{x\}$. Examples: $[3]=3$, $[6.25]=6$, $[-6.25]=-7$, $[22/7]=3$. The source lists: (1) $0<\{x\}<1$ for all real $x$; (2) $\{x\}=0$ exactly when $x$ is an integer; (3) $x-1<[x]\le x<[x]+1$; (4) $[n+x]=n+[x]$ for positive integer $n$ and real $x$; (5) $[-x]=-[x]-1$ if $x$ is not an integer, and $[-x]=-[x]$ if $x$ is an integer. Source correction: property (1) is printed as $0<\{x\}<1$ for all real $x$, contradicting both the definition and property (2) at integers. The correct bound is $0\le\{x\}<1$. The solution uses the definition and this corrected bound.
Real numbers $x,y$ satisfy $[\sqrt{x}]=7$ and $[\sqrt{y}]=11$. Find the smallest possible value of $[x-y]$.
A circle is inscribed in a right triangle. Its point of tangency on the hypotenuse divides that side into lengths 14 and 15. Find the area of the triangle.