1) The number 9 lights up the blue and green bulb. A few other numbers that also light up the pair of light bulbs are; 27, 45, 63, 81 etc.
2) The rule for lighting up the bulbs- blue and green, is every 18th number after 9.We also found that Number 81 and 63 lights up 3 bulbs, while the number 261, lights up all four light bulbs.
3) If you want to see if you can switch on a set of light bulbs instantly, you must find out the rule belonging to their light bulb. Once you've done that, find out if they match with each other,merge them together to create a new rule to figure the number to activate a pair,triad or a quartet of light bulbs.
Our rules we got for Level 1 were:
Blue: Every 6th number after three.
Red: The last digit of the number must be one.
Green: Every 9th number.
Yellow: Every 11th number after eight.