Answer:
459
Step-by-step explanation:
First line:
clock showing 9 o'clock + clock showing 9 o'clock + clock showing 3 o'clock = 9 + 9 + 3 = 21
Second line:
The calculators look exactly the same.
3 * calculators = 30
1 calculator = 10
Third line:
1 bulb + 1 bulb - 1 bulb = 15
Since 1 bulb - 1 bulb = 0, we have 1 bulb + 0 = 15, or
1 bulb = 15
Last line:
Clock showing 9 o'clock = 9
Calculator = 10
3 bulbs = 3 * 15 = 45
Total = 9 + 10 * 45 = 9 + 450 = 459
