Thermodynamics question..?

Question

Given the reaction A + B <--> AB + 210kJ, if an activation energy of 21kJ is required, the activation of the reverse reaction would be...?? would it also be 210kJ? or would it be 21??
also...
When a catalyst is added to a system at equilibrium, there is a decrease in the activation energy of...
a. only the forward reaction
b. only the reverse reaction
c. both forward and reverse reaction
d. neither forward nor reverse

thanks!

Answer 1

21 kJ

c. both forward and reverse reaction