A: 333
The clocks in the first row represent 9 + 9 + 3
The calculators in the second row are each 10 (also 1234 added together is 10)
Each lightbulb in the third row is 15 (15 + 15 – 15) = 15.
Which means each ray above the lightbulb =3
So in the last row:
9 + 9 x (12 + 12 + 12)
9 + 9(36)
9 + 324
333
10/31/20 update from Colin Porteus — thanks for your sharp eyes!!
Hello Robin, can you check the last row on this one please? I get 9 + 9 x (12 + 16+ 16)?? The bottom two globes have 4 threads each x the 4 light marks makes them 16 each?? So consequently I get a result of 405.
Thank you