# Venn diagram question

1. Jan 10, 2016

### Natasha1

1. The problem statement, all variables and given/known data
In a car park there are 25 cars, 5 have L-plates, 12 have GB-plates and 12 have neither.
1) How many have an L-plate but not a GB-plate?
2) How many have a GB-plate and an L-plate?

2. Relevant equations
None here really

3. The attempt at a solution
I got four different drawings each with two venn diagrams.

L-plate =2
Both L and GB-plate = 3
GB-plate = 9

L-plate =1
Both L and GB-plate = 4
GB-plate = 8

L-plate =3
Both L and GB-plate = 2
GB-plate = 10

L-plate =4
Both L and GB-plate = 1
GB-plate = 11

Where am I going wrong?

1) How many have an L-plate but not a GB-plate?
it could be 2, 1, 3 or 4 ?? Not sure which one and why?

2) How many have a GB-plate and an L-plate?
it could be 3, 4, 2 or 1 ?? Not sure which one and why?

2. Jan 10, 2016

### SammyS

Staff Emeritus
That leaves how many cars without tags?
That leaves how many cars without tags?
That leaves how many cars without tags?
That leaves how many cars without tags?
Some of your drawings of Venn diagrams must be incorrect

3. Jan 10, 2016

### Rumplestiltskin

That leaves 13 cars; your three remaining figures should add to 13.

Last edited: Jan 10, 2016
4. Jan 10, 2016

### Natasha1

I think I've got it... It must be

L-plate =1
Both L and GB-plate = 4
GB-plate = 8
Neither plates (outside both Venn diagrams) = 12
As the total is 13 (total of L-plates, GB-plates or both must = 13)

1) How many have an L-plate but not a GB-plate?
Is 1
2) How many have a GB-plate and an L-plate?
Is 4

Could someone please check and let me know if it's right? Many thanks :)

5. Jan 10, 2016

### Rumplestiltskin

Bingo :)

6. Jan 10, 2016

### Natasha1

Many thanks :)