Efficiency of engine, $\eta=60 \%$
Thus, power $=\frac{\text { work / time }}{\eta}=\frac{100}{60} \times \frac{m g h}{t}$
Given, $ m=100\, kg ,\, h=10 \,m , t=5 \,s$
and $g=10 \,ms ^{-2}$
Hence, power $=\frac{100}{60} \times \frac{100 \times 10 \times 10}{5}$
$=3.3 \times 10^{3} \,W$
$=3.3\, kW$