Our school playground was recently closed for construction. For days the kids sat around longing for the slide to open back up. The day the playground was finally finished all of the third graders ran full speed to line up for their turn. As I watched the kids stream out the door I heard Kaden say “That line is going to take forever, forget about it!”

Nah, we can figure it out…. Let’s look at the line. 

Here are the facts:

• Sliding down on pockets takes 7 seconds.

• Sliding down on bellies takes 4 ½ seconds.

• There are 3 third grade classes in line.

 

How many minutes will it take until Kaden gets his turn if 1/3 of the line goes down on their bellies and everyone else is on their pockets?

How many minutes will it take if 30% of the children go down the slide on their pockets? In which line will Kaden wait longer?

Can you express these problems as an equation using an unknown variable?