Problem 5. You felt the new incandescent bulb did not improve the lighting condition as you previously expected. Therefore, you decided to replace the bulb with a luminaire with a dimension of 5ft by 2.8ft centered where the bulb was. The panel of the luminaire is in line with the ceiling. After replacement, you used the light meter to check the illuminance at the center of your desk and got the result of 50 f-c. Therefore, what is the equivalent point-source luminous