# Ratio question

• 03-08-2018, 05:10 PM
Miles
Ratio question
Hi

I'm doing a maths reasoning practice question and I'm wondering why in the solution an eighth is translated as 1 1/8 instead of just 1/8. Please see enclosed.

Plus, can someone point me in the right direction where I can read up on this.

Many thanks

MAttachment 9234
• 03-08-2018, 05:26 PM
JeffM
Quote:

Originally Posted by Miles
Hi

I'm doing a maths reasoning practice question and I'm wondering why in the solution an eighth is translated as 1 1/8 instead of just 1/8. Please see enclosed.

Plus, can someone point me in the right direction where I can read up on this.

Many thanks

MAttachment 9234

If y is bigger than x by 1/8th of x, then

$$y = x + \dfrac{1}{8} * x \equiv \left (1 + \dfrac{1}{8} \right ) * x \equiv \dfrac{9x}{8}.$$

Just different ways to get the same arithmetic result. Really nothing to read up on.
• 03-08-2018, 06:48 PM
Miles
Quote:

Originally Posted by JeffM
If y is bigger than x by 1/8th of x, then

$$y = x + \dfrac{1}{8} * x \equiv \left (1 + \dfrac{1}{8} \right ) * x \equiv \dfrac{9x}{8}.$$

Just different ways to get the same arithmetic result. Really nothing to read up on.

Thanks Jeff, but I need to practice more of these to get a better understanding, so what subject would this come under algebra?
• 03-08-2018, 06:51 PM
Dr.Peterson
Quote:

Originally Posted by Miles
Thanks Jeff, but I need to practice more of these to get a better understanding, so what subject would this come under algebra?

This is the same concept as "percent increase". Reading about that may help.

Or, as Jeff showed, it just comes from applying algebra to the problem: "increase x by fraction m" means "add m times x to x itself" (start with x, and increase it by m times itself).
• 03-08-2018, 07:14 PM
Miles
Quote:

Originally Posted by Dr.Peterson
This is the same concept as "percent increase". Reading about that may help.

Or, as Jeff showed, it just comes from applying algebra to the problem: "increase x by fraction m" means "add m times x to x itself" (start with x, and increase it by m times itself).

Ah! Now I get it. Thanks
• 03-09-2018, 02:57 PM
stapel
Quote:

Originally Posted by Miles
Thanks Jeff, but I need to practice more of these to get a better understanding, so what subject would this come under algebra?

Fractions and percentages are usually pre-algebra, or before pre-algebra. ;)