Question

Which of the following exerts the greatest pressure on the ground?

Answer 1

Pressure = (weight) / (area supporting the weight).

From the fraction, you can see that more weight produces more pressure,
and less area produces more pressure. 

So, for the greatest pressure, you want the greatest weight supported by
the smallest area.

That would be the 55-kg boy, standing on one foot.

Answer 2

A 55-kg boy standing on one foot is my answer. When you stand on two feet, you don't really exert a lot of pressure because your weight is resting on two feet. And 55-kg sure weighs more than 35. so my answer is 2.