Looking at the graph - when was the person moving fastest? Slowest?
At Holborn underground station there is a very long escalator. Two people are in a hurry and so climb the escalator as it is moving upwards, thus adding their speed to that of the moving steps. . . .
My measurements have got all jumbled up! Swap them around and see if you can find a combination where every measurement is valid.
A garrison of 600 men has just enough bread ... but, with the news that the enemy was planning an attack... How many ounces of bread a day must each man in the garrison be allowed, to hold out 45. . . .