If 12000 people voted in the election, how many people were from 50 to 64 years old

Assuming that this question is based on a graph, and that this graph tells us that people 50-64 years make up 35% of all the voters, then it would mean that
35%of 12000=

So, assuming that people at age 50-64 make up 35% of the voters, then 4200 of them voted.