What is the answer to the hourglass on cool math 4 kids?

Answer 1

Measuring 15 minutesStart by flipping both the 7 and 11 jar over and hitting start.

You should now have 4 in the 11 jar and 0 in the 7. Don't hit start yet.

Now flip the 7 jar over so you have 7 in the 7 jar and 4 in the 11 jar.

Now you can hit start.

You should now have 3 on top and 4 on bottom of the 7 jar and 0 in the 11. Before you hit start, flip the 7 jar so you have 4 on top.

Then hit start.

Measuring 24 minutesStart by flipping both the 7 jar and 11 jar over and hitting start.

You should now have 4 in the 11 jar and 0 in the 7 jar. Don't hit start yet.

Flip over the 7 jar so you have 7 in the 7 jar and 4 in the 11 jar.

Now hit start.

You should now have 3 on top and 4 on bottom of the 7 jar and 0 in the 11. Don't hit start!

Now flip the 11 jar so 11 is on top. Now hit start.

Now the 7 jar should have 0 and the 11 jar should have 8 on top and 3 on bottom. Don't hit start.

Flip the 11 jar so 3 is on top and 8 is on bottom. Now you can hit start.

You should now have 0 in both the 7 jar and 11 jar.

Before hitting start, flip over just the 7 jar so 7 is on top.

Now hit start