Question 936415
let ages  of 4 people born 4 years apart be x,x+4,x+8,x+12 
sum of their ages = 88
  x+(x+4)+(x+8)+(x+12)=88
  x+x+4+x+8+x+12 = 88
     4x+24= 88
 move 24 to the right
      4x = 88-24
    4x  = 64
  divide with 4 on both sides
 {{{ 4x/4  =64/4}}}
     {{{ x=16}}}
  x= 16
  x+4 = 20
 x+8 = 24
 x+12 = 28
 age of youngest is 16 years