The number c is the by multiplying by to create the equivalent ratio.
We are given ratio of number of boys to number of girls = 8:7
On multiplying c by 8, we get 8c and on multiplying c by 7 we get 7c.
Therefore, number of boys = 8c and
number of girls = 7c.
Total number of girls and boys = 195.
Number of boys + number of girls = 195.
We can setup an equation now
8c + 7c = 195.
Adding 8c and 7c we get 15c.
Therefore 8c + 7c = 195 equation would become
15c=195.
Dividing both sides by 15, we get
15c/15 = 195/15.
c = 13.
Therefore, value of number c is 13.
Fourth option is correct.
