Question

Jenny has to get her wheelchair on the sidewalk. Which simple machine will she need a lever or inclined plane why?

Answer 1

She will need an inclined plane since it is stable and cheap: no moving parts, no ball bearings, no complex mechanisms. Inclined plane is easy to use for her and others, but of course the angle of inclination must be reasonable not to require much force for Jenny.
A lever is unstable, and the only way make it stable and reliable is use it in elevating mechanism, but it is expensive, requires electricity to operate and has many moving parts. Lifting mechanism with lever will be effective if she has to get her wheelchair on high sidewalk.
Answer
Inclined plane