Two seniors and a freshman took the honors at this year’s Northern Illinois University Mathematics Contest.

The 26th running of the annual event was held March 23. The winners were recognized Sunday, April 17, at the **Department of Mathematical Sciences’** Awards Ceremony and Reception.

**Chi Zhang**, a senior **computer science**/mathematical sciences major from Qingdao, China, won first place for the third year in a row, and was awarded the first prize of $100. **Xiaoyang Bi**, a senior mathematical sciences (actuarial science) major from Vernon Hills, took the second prize of $75. **Taylor Brysiewicz**, a freshman mathematical sciences major from Bartlett, finished third and received $50.

The annual **Northern Illinois University Mathematics Contest** has a format where freshmen and sophomores have a fair chance to compete with juniors and seniors. The underclassmen have fewer restrictions on their choice of problems to attempt.

The contest is open to all full-time undergraduates at NIU. Each contestant turns in solutions to a choice of six out of 11 problems. Topics this year ranged from high school-level algebra, geometry and elementary number theory through calculus, linear algebra and differential equations.

Professors **Harvey Blau** and **Gleb Sirotkin** supervised the competition, which drew 12 student participants.

Here is the easiest problem from this year’s contest: It is spring, and there are 12 hours of daylight. A caterpillar climbs a vertical wall at a speed of 1 foot per hour during the day, and then sleeps for 12 hours of darkness, during which it slides downward at ½ foot per hour. The wall is 48 feet high. How long will it take the caterpillar to reach the top of the wall?

A more difficult problem, although it only involves knowledge of matrix multiplication from linear algebra, was the following: Does there exist a 3-by-3 matrix with four positive entries and five zero entries that has some power with all positive entries? Prove your answer.