The answer is 8 lux. Using the formula E= I/s^2, E stands for the illuminance on the surface that we are trying to solving, I stands for the intensity of the light from the sources it is candelas in the problem that we’re solving, and S stands for the distance from the light source to the surface it should be in meters.
E= I/s^2
E= 72/3^2
E=72/9
E= 8
