Answer:
The weight would be doubled
Step-by-step explanation:
The weight of an object on Earth is equal to the gravitational attraction exerted by the Earth on the object:

where
G is the gravitational constant
m is the mass of the object
M is the mass of the Earth
r is the distance between the object and the Earth's center
We see that the weight (F) is directly proportional to the Earth's mass (M): so, if the Earth had twice the mass that it does now (M'=2M), then the weight F would be also doubled, in fact:
