Answer: 
In part (a) 
Step-by-step explanation:
Work done when climbed upstairs is explained in terms of change in potential energy. 
Work=Δ(Mass.gravity.height) or W=m.g.h
Mass and gravity are constant during motion but height differs in part a from part b. The speed of climbing doesn't affect the value of work. 
Height (in terms of the number of stairs) in part a is 40 stairs more than in part b.