Răspuns :

m+t+f=90
t=m+5
m=f+23

t=m+5
t=f+23+5
t=f+28

f+23+f+28+f=90
3f+51=90
3f=90-51
3f=39
f=39:3
f=13 ani

tata=13+28
tata=41
mama=13+23
mama=36
                                        90-59=39
                                        39:3=13(fiul)
                                        13+28=41(tata)
                                        13+23=36(mama)
                                         V: 13+41+36=90
                                         R:90 ani