# Math Help - Equation

1. ## Equation

Hi guys just wondering if you could help me out with this question i know the answer is 10 but im not sure how the eqution is set up?
The amount of sleep ( s hours) a child needs depends on its age (A years)., and is given bu the foruma above S=15-1/2 (half)A

If a girls age is equal to the number of hours she should be sleeping how old is she
Thanks

Sam

2. ## Mistake

OOps this is in the wrong forum sorry

3. Originally Posted by bassmansam
Hi guys just wondering if you could help me out with this question i know the answer is 10 but im not sure how the eqution is set up?
The amount of sleep ( s hours) a child needs depends on its age (A years)., and is given bu the foruma above S=15-1/2 (half)A

If a girls age is equal to the number of hours she should be sleeping how old is she
Thanks

Sam
$S = 15 - \frac{1}{2} A$

$S = A$ (Given)

So S and A = $x$

$x = 15 - \frac{1}{2} x$

[Multiply both sides by 2]

$2x = 30 - x$

$3x = 30$

$x = 10$

4. Originally Posted by bassmansam
OOps this is in the wrong forum sorry
Isn't this a middle school problem?

5. im at university so i would guess it is a university question?

6. Originally Posted by bassmansam
im at university so i would guess it is a university question?
I'm not trying to be funny, but I did stuff like this in grade 10...

7. well i am from england, maybe that is why?

8. Originally Posted by bassmansam
well i am from england, maybe that is why?
What are you studying, if i may ask?

9. Im studying Computing

10. Originally Posted by bassmansam
Im studying Computing
Oh that explains it. It's not very heavy on maths.