You may also like

problem icon

Building Tetrahedra

Can you make a tetrahedron whose faces all have the same perimeter?

problem icon

Ladder and Cube

A 1 metre cube has one face on the ground and one face against a wall. A 4 metre ladder leans against the wall and just touches the cube. How high is the top of the ladder above the ground?

problem icon

Days and Dates

Investigate how you can work out what day of the week your birthday will be on next year, and the year after...

Factor List

Stage: 4 Short Challenge Level: Challenge Level:2 Challenge Level:2

When Tina chose a number N and wrote down all of its factors, apart from $1$ and N, she noticed that the largest of the factors in the list was $45$ times the smallest factor in the list. How many numbers N could Tina have chosen for which this is the case?
 
 
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
  
 
 

This problem is taken from the UKMT Mathematical Challenges.
View the archive of all weekly problems grouped by curriculum topic