Question 1057892
Children: I, M, N
N = I/3
M = I-5
: 
I+M+N = 23 substitute:
I+I/3+I-5 = 23
2I+I*1/3-5 = 23 On the left, 2I+I/3 = 7I/3
7I/3-5 = 23
7I/3 = 28 multiply both sides times 3
7I = 84
I = 12 Ivan is 12
Nadia is 12/3 = 4
Maria is 12-5 = 7