Answer:
8n+12=36, triplets are 8 years old
Step-by-step explanation:
total age is 36
one of them is 12 years old so -> 36-12 = 24
three triplets so 24/3 = 8
there are three 8 years olds and one 12 year old. n = 3
3n + 12 = 36
3n = 24
n = 8 (the triplets)
another child: 12 years
