Friday, April 13, 2012

Stumped on our math question?

This week, we heard from a Young Achiever with a special gift of solving equations and excelling in math.

After all, Lloyd Liu scored a perfect 800 on the math portion of the SAT - as a seventh grader.

In the story, we challenged readers with a practice math question from Lloyd's MathCounts School Handbook.

We posed this question:
Q: If a set of seven positive integers has a mean of 5, what is the greatest possible integer in the set?
The answer: 29.

A few of you were stumped, so we went back to Lloyd's math teacher, Andria Sullivan for an explanation:

For seven positive integers to have a mean of 5, the sum of the integer must be 7*5=35. If one of the integers is to be as great as possible the other 6 would have to be the least possible meaning 1. Therefore 1+1+1+1+1+1+29=35. So, the greatest integer is 29.

Want to continue to test your math skills?
Here is another problem to keep you busy:

Q: Marika shoots a basketball until she makes 20 shots or until she has made 60 percent of her shots, whichever happens first. After she has made 10 of her first 20 shots, how many more shots in a row does she have to make to be finished?
See below for answer.

Question source: MATHCOUNTS School Handbook 2004-05.
Photo: Lloyd Liu, 13, a seventh grade student at Randolph Middle. Photo by Brittany Penland.
Question answer: 5.


The Flying Engineer said...

Haha, Cool! Good job kid! Keep up the good work!