Answer to Problem # 16:
Bro = 2 x Me Bro - Me = 13
Substitute: (2 x Me) for Bro
(2 x Me) - Me = 13 2 Me - Me = 13
Me = 13 (ANSWER)
Note: If your brother will be 13 years older than you in 10 years
from now, he is now (and will always be) 13 years older than you !