Answer:
143.815 N
Explanation:
when a person is pushing a carton in an inclined plane there is two forces acting against  the applied force,
- component of gravity or mgsinθ
the carton goes up ( constant velocity ) only if sum of these two forces becomes equal to applied force
from the question,
weight of the carton,mg = 245 N
angle of incline,θ = 15°
coefficient of friction, μ = 0.340
∵ the applied force, F = mgsinθ + μmgcosθ
                  = mg ( sinθ + μcosθ)
                  = 245 ( sin 15° + 0.340 cos 15°)
                  = 245 ( 0.259 + 0. 328)
                  = 143.815 N
