Răspuns :
I + B = 47
B = I + 7
I + I + 7 = 47
2I = 47 - 7
2I = 40
I = 40 : 2
I = 20 TIMBRE ARE IOANA
B = 20 + 7
B = 27 TIMBRE ARE BIANCA
B = I + 7
I + I + 7 = 47
2I = 47 - 7
2I = 40
I = 40 : 2
I = 20 TIMBRE ARE IOANA
B = 20 + 7
B = 27 TIMBRE ARE BIANCA