I'm just trying to do this homework and I'm struggling with a question in particular.

Tyrone, John, and Pedro all have their own ethnic group in the local community. John's ethnic group work long hours or goes to school being a productive member of society. Tyrones ethnic has the local government take money from Johns in order to not have to work. Pedros is just happy to be there and kinda vibes around.
John's and Pedro's ethnic groups combined equals 87% of the population. This 87% commits 50% of violent crimes. What percent of violent crime does Tyrones ethnic group commit?

87:50 ?:13