Question

at the craft store, dwayne bought a bag of red and blue marbles. he received 40 marbles in all. 30 of the marbles were red. what percentage of the marbles were red? write your answer using a percent sign (%).

Explanation:

Step1: Recall the percentage formula

The formula for percentage is $\text{Percentage}=\frac{\text{Part}}{\text{Whole}}\times100\%$. Here, the number of red marbles is the part ($30$) and the total number of marbles is the whole ($40$).

Step2: Substitute values into the formula

Substitute the values into the formula: $\text{Percentage}=\frac{30}{40}\times100\%$.

Step3: Simplify the fraction

Simplify $\frac{30}{40}$ to $\frac{3}{4}$. Then $\frac{3}{4}\times100\% = 0.75\times100\%$.

Step4: Calculate the percentage

$0.75\times100\%=75\%$.

Answer:

$75\%$