You are Here: Home >< GCSEs

Help me with this tricky question! watch

Announcements
1. jess has a 4 digit password for her mobile phone. each digit can be between 0 and 9 inclusive.Jess would like to choose an even umber.the code can start with a zero.How many possible ways are possible now? answer is 5000 btw !
2. 10*10*10*10 / 2
3. (Original post by iow16)
10*10*10*10 / 2
why is there a 2 tho????
4. (Original post by shaaruka)
why is there a 2 tho????
Even eliminates half the possible numbers.
5. 0-9 digits has 10 different possibilities
There are 4 digits, so you do:

10*10*10*10 = 10,000

Now, the number has to be even. If there were 10 numbers we could split them into even and odd
0,2,4,6,8 - EVEN
1,3,5,7,9 - ODD

There are 5 even and 5 odd. This means that 5/10, or a 1/2 of the numbers will be even. So we do:

10,000 / 2 = 5,000
6. Only half the numbers between 0 and 10000 are even.

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: November 14, 2017
Today on TSR

Uni league tables

Do they actually matter?

University open days

• University of Warwick
Sat, 20 Oct '18
• University of Sheffield
Sat, 20 Oct '18
• Edge Hill University
Faculty of Health and Social Care Undergraduate
Sat, 20 Oct '18
Poll
Useful resources

Study tools

Essay expert

Learn to write like a pro with our ultimate essay guide.

See where you can apply with our uni match tool

Make study resources

Create all the resources you need to get the grades.

Organise all your homework and exams so you never miss another deadline.

Resources by subject

From flashcards to mind maps; there's everything you need for all of your GCSE subjects.

Find past papers

100s of GCSE past papers for all your subjects at your fingertips.