Answer:
2/3 hour or 40 minutes
Step-by-step explanation:
They work at the same speed.
In 1/2 hour, they painted 3 panels.
In 1 hour, they would paint 6 panels.
In 1 hour, Dan would paint 3 panels.
Their individual speed is 3 panels per hour.
2 panels is 2/3 of 3 panels.
It will take 2/3 hour to paint 2 panels.
2/3 hour = 2/3 * 60 minutes = 40 minutes
