Articles by Michael Dinerstein

Manhattan GMAT Challenge Problem of the Week – 19 May 2010

by Michael Dinerstein on May 19, 2010

Welcome back to this week’s Challenge Problem! As always, the problem and solution below were written by one of our fantastic instructors. Each challenge problem [...]


Manhattan GMAT Challenge Problem of the Week – 11 May 2010

by Michael Dinerstein on May 11, 2010

Welcome back to this week’s Challenge Problem! As always, the problem and solution below were written by one of our fantastic instructors. Each challenge problem [...]


Manhattan GMAT Challenge Problem of the Week – 6 May 10

by Michael Dinerstein on May 6, 2010

Welcome back to this week’s Challenge Problem! As always, the problem and solution below were written by one of our fantastic instructors. Each [...]


Manhattan GMAT Challenge Problem of the Week – 29 Apr 10

by Michael Dinerstein on April 29, 2010

For which of the following functions f(x) is the relation f(f(x)) = f(f(f(f(x)))) NOT true for at least some values of xnot equal to zero?


Manhattan GMAT Challenge Problem of the Week – 22 Apr 10

by Michael Dinerstein on April 22, 2010

Welcome back to this week’s Challenge Problem! As always, the problem and solution below were written by one of our fantastic instructors. Each challenge problem [...]


Manhattan GMAT Challenge Problem of the Week – 16 Apr 10

by Michael Dinerstein on April 16, 2010

A number of eggs dyed various colors were hidden for an egg hunt. How many eggs in total were hidden?


Manhattan GMAT Challenge Problem of the Week – 8 Apr 10

by Michael Dinerstein on April 8, 2010

At the beginning of year 1, an investor puts p dollars into an investment whose value increases at a variable rate of [pmath]x_n[/pmath]% per year, where n is an integer ranging from 1 to 3 indicating the year. If 85 < [pmath]x_n[/pmath] < 110 for all n between 1 and 3, inclusive, then at the end of 3 years, the value of the investment must be between


Manhattan GMAT Challenge Problem of the Week – 1 Apr 10

by Michael Dinerstein on April 1, 2010

If ab ≠ 0 and a ≠ -3b, what is the value of (4a + 6b)/(a + 3b)?


Manhattan GMAT Challenge Problem of the Week – 25 Mar 10

by Michael Dinerstein on March 25, 2010

Welcome back to this week’s Challenge Problem! As always, the problem and solution below were written by one of our fantastic instructors. Each challenge problem [...]


Manhattan GMAT Challenge Problem of the Week – 19 Mar 10

by Michael Dinerstein on March 19, 2010

Welcome back to this week’s Challenge Problem! As always, the problem and solution below were written by one of our fantastic instructors. Each challenge problem [...]


Manhattan GMAT Challenge Problem of the Week – 11 Mar 10

by Michael Dinerstein on March 11, 2010

Welcome back to this week’s Challenge Problem! As always, the problem and solution below were written by one of our fantastic instructors. Each challenge problem [...]


Manhattan GMAT Challenge Problem of the Week – 4 Mar 10

by Michael Dinerstein on March 4, 2010

Welcome back to this week’s Challenge Problem! As always, the problem and solution below were written by one of our fantastic instructors. Each challenge problem [...]


Manhattan GMAT Challenge Problem of the Week – 26 Feb 10

by Michael Dinerstein on February 26, 2010

Welcome back to this week’s Challenge Problem! As always, the problem and solution below were written by one of our fantastic instructors. Each challenge problem [...]


Manhattan GMAT Challenge Problem of the Week – 18 Feb 10

by Michael Dinerstein on February 19, 2010

Set S consists of 5 values, not necessarily in ascending order: {4, 8, 12, 16, x}. For how many values of x does the mean of set S equal the median of set S?