Question

Jim, Carla and Tomy are members of the same family.  Carla is 5 years older than Jim.  Tomy is 6 years older than Carla.  The sum of their 3 ages is 31 years. How old is each one of them?

Answer 1

X - Jim
y - Carla
z - Tomy

$y=x+5\\ z=y+6\\ x+y+z=31\\\\ x=y-5\\ z=y+6\\ x+y+z=31\\\\ y-5+y+y+6=31\\ 3y=30\\ y=10\\\\ x=10-5\\ x=5\\\\ z=10+6\\ z=16$

Answer 2

let the age of jim be x
carla's age= x+5
tomy's age= 6+5+x
sum of their ages=31
x+x+5+x+5+6=3x+16=31
3x=31-16
   =15
x=15 divided by 3
     = 5
jim's age=5
carla's age=10
tomy's age = 16