Answer:
John received 10% of the overall votes.
Step-by-step explanation:
Let us assume that the number of votes John got = m
So, the number of votes Vivienne received = 3 times (John's share )
= 3 times m = 3 m
Also, The number of Votes Nassim received = 2 times ( Vivienne's share)
2 x (3 m) = 6 m
Total Votes in the grade 6
= Votes received by { John + Vivienne + Nassim}
= m + (3 m) + (6 m) = 10 m
Hence, the total number of students who voted in grade 6 = 10 m

= 
or, The percentage of John's Votes = 10%
Hence, John received 10% of the overall votes.
The circumference of the circle is actually the perimeter ( length of the boundary ) of the circle . And a part of the circle which lies between two distinct points on the circumference of the circle is called an arc . If the length of the arc is less than half the circumference , it is called minor arc and remaining portion which is more than half of the circle ( but natural ) is called major arc .
When these two points , which make the arc are joined separately to the centre of circle , these arms make angle at the centre . This is called the angle subtended by the arc at the centre of the circle .
There is a beautiful logical relation exists between arc length and the angle , the arc makes ( subtends ) at the centre of the circle . This relation is as under , the wholle circle subtends an angle of 360 degree at the centre . Half the circumference subtendr 360 / 2 ie 180 degree at the centre . The logical relation becomes Arc Length = Circumference × angle in degrees it ( the arc ) subtends at the centre of the circle / 360 degree . So the answer is very simple :- The Arc Length = 36 × 90 / 360 or 9 units ( may be centimetres or metres or inches , feet , yards , etc ) . Which is definitely length of the minor arc . The length of the major arc ( remaining portion of the circumstance ) is 36 - 9 = 27 units . Hence the required answer of the sum is 9 units .
5*5+5=30
5*5-15=10
30/10= 3