Answer:
d = 0.604 m
Explanation: set 0 GPE at max spring compression, then
total E = U = 1/2kx^2 = 1/2 25N/m (0.1m)^2 = 0.125 J
max height,
GPE = 0.125 J = mgh = 0.05kg 9.8m/s^2 h
h = 0.255 m
Along slope, d = 0.255m / sin25°
d = 0.604 m
It's possible they want the distance from the end of the spring -- that's 0.504 m