Here are the given information:
1. 7 red beads for every 4 blue beads
2. total of 44 beads (red and blue)
Find: the number of red beads
Solution:
We can solve this in two ways. We can solve this using proportion or we can solve this by counting.
Let's start counting first. Let's say 7 red beads and 4 blue beads is 1 set. So, for every set, we already have 7 + 4 = 11 beads in total.
First set = 7 red bead + 4 blue beads = 11 beads
Second set = 7 red bead + 4 blue beads = 11 beads
Third set = 7 red bead + 4 blue beads = 11 beads
Fourth set = 7 red bead + 4 blue beads = 11 beads
If we add all the 4 sets, we have a total of 44 beads. If we add all the RED beads only, we get 7 red beads x 4 sets = 28 red beads.
Therefore, Lily used 28 red beads.
Now, using proportion, we can have this equation:
[tex]\frac{7\text{red beads}}{4\text{blue bead}}=\frac{x\text{ red beads}}{(44-x\text{ red)blue beads}}[/tex]where x = the total number of red beads and we got 44 - x as the number of blue beads.
The next thing that we need to do here is to solve for x.
1. To solve for x, do cross multiplication first.
[tex]7(44-x)=4x[/tex]2. Multiply 7 to the numbers inside the parenthesis.
[tex]308-7x=4x[/tex]3. Add 7x on both sides of the equation.
[tex]\begin{gathered} 308-7x+7x=4x+7x \\ 308=11x \end{gathered}[/tex]4. Lastly, divide both sides by 11.
[tex]\begin{gathered} \frac{308}{11}=\frac{11x}{11} \\ 28=x \end{gathered}[/tex]As we can see, the value of x = 28. Lily used 28 red beads.
