A person standing on a spring balance inside a stationary lift measures 60   kg . The weight of that…

When lift is at rest

$N=mg$

$\Rightarrow 60\times 10=600 \mathrm{N}$

When lift moves with downward acceleration. In frame of lift pseudo force will be in upward direction.

$N^{\text{'}}=M\left(g-a\right)$

$\Rightarrow 60\left(10-1.8\right)$

$N^{\text{'}}\Rightarrow 492 \mathrm{N}$