The maximum magnitude of the net force on the box is 20 N, which is only possible if the boy and the girl pull the box together in the same direction, horizontally and parallel to the ground.
The minimum magnitude of the net force on the box is 0 N, which will occur when the boy and the girl pull the box together in the parallel but opposite direction.
If either of them pulls at an angle from the horizontal, then the magnitude of the net force will be between 0 N and 20 N.
According to Newton's Second Law of Motion :
The Force acting on an Object is equal to Product of Mass of the Object and Acceleration produced due to the Force.
Force acting = Mass of the Object × Acceleration
Given : Force = 50 newton and Mass of the Object = 10 kg
Substituting the respective values in the Formula, we get :
50 N = 10 kg × Acceleration

Acceleration of the Object = 5 m/s²
The answer is d.5 your welcome
Dekaliter is 10 times bigger than 1 liter.
1 Dekalite = 10 Liters