Final answer:
To find out what percent of the pens were yellow, divide the number of yellow pens by the total number of pens and multiply by 100, resulting in 15% of the pens being yellow.
Step-by-step explanation:
To calculate what percent of the pens were yellow, you first need to know the total number of pens and then find out the proportion that is yellow.
Add the number of yellow pens to the number of purple pens to get the total, which is
60 yellow pens + 340 purple pens = 400 total pens.
Next, divide the number of yellow pens by the total number of pens and multiply by 100 to get the percentage.
The calculation would be:
(60 yellow pens ÷ 400 total pens) × 100 = 15% yellow pens.
Therefore, 15% of the pens were yellow.