Take the upside down mirror image of the equation and then read it from reverse .
81 * 9 = 801 will become 108 = 6 * 18

i’m not sure but i don’t think any mobile would be charged using these extensions . Cause judging by the picture i think the extensions are 3 -pin charger cables . And the main socket supports only the 2 pin charger cable , so no mobile would be able to get charged using these extensions .
But if the extension cables are 2 pin charger then the total number of mobiles that can be charged at a time are 12 .
plug one extension with 4 plug points to the main socket and then plug the remaining extension cables to this extension .
so we will have 12 free plug points now to charge the mobiles .

A Stapler .

its reflection or shadow .

still the 10 cows that he had .

Heroine .

Nature’s call i guess .

Experiences or Life lessons may be .

Well matching the colors of the circles  and their correspondent value with the last figure of circles i think the answer is
14
Here is the thought process –
In first figure the values of each circle (from bottom to up)are =
X + X-5 + X-10 + X-15 + X-20 = 15
X is the darkest blue
So, x comes out to be 13
First row- 13,8,3,-2,-7
similarly the next figure values are = 19,14,9,4,-1
the values for the third figure = 25,20,15,10,5
the forth circle values (matching the colors of the circles with the previous three ) = 13,19,25,-7,-1
adding the values  of circles for each series we have the series as 15,45,75,49
so the fifth circle values according to their colors are = -7,-1,-2,4,20 
so the total of this series of circles are = 14