Two masses m₁=5 kg and m₂=4.8 kg tied to a string are hanging over a light frictionless pulley. What is the acceleration of the masses when lift is free to move? (g=9.8 m/s²)

The stem's 'when lift is free to move' describes nothing the question sets up -- no lift appears anywhere else in it -- and the printed answer is the ordinary fixed-pulley result, which is what is worked here.

Idea: the ordinary Atwood result a=((m₁-m₂)g)/(m₁+m₂), with the numbers chosen so that the arithmetic collapses.

m₁-m₂=5-4.8=0.2 kg.

m₁+m₂=5+4.8=9.8 kg.

a=(0.2×9.8)/(9.8)=0.2 m/s².

The total mass happens to equal g numerically, so the 9.8 cancels and the mass difference in kilograms is the answer in m/s².

On the stem's phrase: 'free to move' means the masses are released, not that the support is falling. A freely falling support would give zero, and zero is not among the options.