Hi,
My name is Rizwan and I m in gr.6. My question is: 3 sixth graders painted 4 walls in 3.5hrs. At that rate, how many walls would they paint in 7 hrs. Thanks

The three of them worked for 3.5 hours and had 4 walls painted. If they continued for another 3.5 hours they would paint another 4 walls. But 3.5 + 3.5 = 7, and hence in 7 hours they would have painted 8 walls.