Question

Colleen is knitting a scarf. For every 45 pieces of blue yarn she uses, she uses 18 pieces of red yard. What equation can be used to represent the proportional relationship between the amount of blue yarn, b, and red yard, r, that Colleen uses when knitting a scarf?

Answer 1

Given:

For every 45 pieces of blue yarn, Colleen uses 18 pieces of red yard.

To find:

The equation that can be used to represent the proportional relationship between the amount of blue yarn, b, and red yard, r, that Colleen uses when knitting a scarf.

Solution:

We have,

Blue yarn = 45 pieces

Red yarn = 18 pieces

It is given that there is a proportional relationship between the amount of blue yarn, b, and red yard, r, that Colleen uses when knitting a scarf. So,

$\dfrac{r}{b}=\dfrac{18}{45}$

$\dfrac{r}{b}=\dfrac{2}{5}$

$r=\dfrac{2}{5}b$

Therefore, the required equation is $r=\dfrac{2}{5}b$.