We will first convert all units to meters and then solve the problem.
We are given that:
1000 mm = 1 m
120 mm = ?? meters
using cross multiplication:
120 mm = (120*1) / 1000 = 0.12 m
Now, when the two objects are placed over each other, their total height is the result of summation of both heights, therefore:
total height = 0.12 + 1.5 = 1.62 m
Based on the above calculations, the correct choice is:
b) 1.62 m