Prime factors

6th May 2005 at 01:00
The five prime numbers 3, 7, 11, 13 and 37 are special. When they are multiplied together, the result is 111 111.

3 x 7 x 11 x 13 x 37 =111111 What is the product of 23 and these five prime numbers? Five of the digits are the same. Why is this?

SOLUTIONS District nurse (ages 8 to 13). 1 Possible routes for a single visit to each town are ABCDA (or reverse), ABDCA (or reverse) or ACBDA (or reverse). The shortest route is 40 miles. 2 For the week of January, possible routes are ACDBCA (or reverse), which is 53 miles long; or ABCBCA (or reverse) or ADCBCA (or reverse), each of which is 51 miles long. Prime factors (ages 11 to 14) 23 x 111 111 = 2 555 553, because 2 + 3 = 5.

Subscribe to get access to the content on this page.

If you are already a Tes/ Tes Scotland subscriber please log in with your username or email address to get full access to our back issues, CPD library and membership plus page.

Not a subscriber? Find out more about our subscription offers.
Subscribe now
Existing subscriber?
Enter subscription number


The guide by your side – ensuring you are always up to date with the latest in education.

Get Tes magazine online and delivered to your door. Stay up to date with the latest research, teacher innovation and insight, plus classroom tips and techniques with a Tes magazine subscription.
With a Tes magazine subscription you get exclusive access to our CPD library. Including our New Teachers’ special for NQTS, Ed Tech, How to Get a Job, Trip Planner, Ed Biz Special and all Tes back issues.

Subscribe now