Suppose an astronaut were to visit a planet where the force of gravity is half that of earth. his mass on that planet would be:

a. zero
b. the same as his earth mass
c. twice his earth mass
d. half his earth mass

"Mass" is what YOU ARE.  It doesn't matter whether you're on Earth, on the moon, on an asteroid, on a meteoroid, on the sun, swimming in chicken soup on Saturn, or in a space capsule falling from one solar system body to another one.  Your mass DOESN'T change.

Whatever mass the astronaut had after he ate that steak dinner just before he was launched, THAT's the mass he has while he's on the way to another planet, and THAT's the same mass he'll have when he gets there.  It makes no difference what the gravity is like on the other planet.  His mass will not change. (choice-B)

Only his WEIGHT changes when he's in different places.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards