Basically the cheetah is running 31.5km/h faster than the gazelle. So to determone how long it will take to cover 9mm at that speed, you have to a lot of work. If you skip all of that work, the answer is 1.60m seconds
Answer
given,
high temperature reservoir (T_c)= 464 K
efficiency of reservoir (ε)= 25 %
temperature to decrease = ?
increase in efficiency = 42 %
now, using equation




T_C = 348 K
now,
if the efficiency is equal to 42$ = 0.42



The answer would be a i'm pretty sure