Category Archives: MATHCOUNTS

AMC 10 Exercise – 2

What is the tens digit of $2019^{2020}-2021$? All the numbers $2$,$3$,$4$,$5$ are assigned to the four faces of a tetrahedron. For each of the four vertices of the tetrahedron, a product of three numbers are computed, where the three numbers … Continue reading

Posted in Math Classes, MATHCOUNTS | Comments Off on AMC 10 Exercise – 2

AMC 10 Exercise – 1

Two years ago Pete was three times as old as his cousin Claire. Two years before that, Pete was four times as old as Claire. In how many years will the ratio of their ages be $2:1$? Two right circular cylinders … Continue reading

Posted in Math Classes, MATHCOUNTS | Comments Off on AMC 10 Exercise – 1

A MATHCOUNTS Problem with Multiple Answers 🙂

The following is MATHCOUNTS 2012 National Competition Sprint Round Problem 22: In circle $O$, shown, $OP=2$ units, $PL=8$ units, $PK=9$ units and $NK=18$ units. Points $K$, $P$ and $M$ are collinear, as are points $L$, $P$, $O$ and $N$. What … Continue reading

Posted in Fun Math Facts, Geometry, MATHCOUNTS, Trigonometry | Comments Off on A MATHCOUNTS Problem with Multiple Answers 🙂

AMC 8/MathLeague Mock Test – 1

If the hands on a circular clock start at midnight, what number will the hour hand point to 1000 hours later? $(A)\ 2 \ \ \ \ \ \ \ \ \ (B)\ 4 \ \ \ \ \ \ … Continue reading

Posted in Math Classes, MATHCOUNTS | Comments Off on AMC 8/MathLeague Mock Test – 1

MathCounts Training – Number Theory – 6

________ What is the sum of all positive two-digit integers with exactly 12 positive factors? $$ $$ ________ What is the sum of the three numbers less than 1000 that have exactly five positive integer divisors? $$ $$ ________ The … Continue reading

Posted in Algebra, Math Classes, MATHCOUNTS | Comments Off on MathCounts Training – Number Theory – 6