Answer:
3.43 m
Explanation:
f = 100 mm
u = - 103 mm
Let v be the distance between the screen and the lens of the projector.
Use lens equation
1 / f = 1 / v - 1 / u
1 / 100 = 1 / v + 1 / 103
1 / v = 1 / 100 - 1 / 103
1 / v = (103 - 100) / (100 x 103)
1 / v = 3 / 10300
v = 3433.33 mm = 3.43 m