After teaching ratio and proportion, I set a homework including the following.
A man climbs to the top of a local beauty spot and estimates he can see for 25 miles. Next day, he takes his friend, how far can the two men see?
There is an audience of 400 at a concert, and it takes the orchestra 20 minutes to play a particular piece of music. Next night there are 600 in the audience, how long will it take now?
There were proper questions too, but quite a few fell for these!