2013 - 39, 40 & 41

And we now wrap up the 2013 test. Next set will be from the early years.

Some algebra for today. Typical for the last questions, there is one infinite geometric series. Here is the one for this test:

Difficulty: Medium.

Difficulty: Hard, sort of.  The units digit is easy but the tens digit follows a more complicated pattern and takes a while to find.

Difficulty: Medium, but the kids will find it Hard.

Standard instructions for this series: No calculator allowed. Express answers in reduced form. Rationalize denominators. Radicals must be reduced. All numbers are base ten unless otherwise specified. Do not approximate radicals or π. Leave such answers as 1025π or √39, for example. Source: UVM Math Contest 2013

answer 39, answer 40, answer 41. Published 5/6.