Asked by Kaur
After five years the sum of ages of father and his son will be 70. Then four years ago sum of their ages was
Answers
Anonymous
52
Bosnian
F = father's present age
S = son's present age
After five years father will be F + 5 yrs old.
After five years son will be S + 5 yrs old.
After five years, the sum of their years will be 70.
F + 5 + S + 5 = 70
F + S + 10 = 70
F + S = 70 - 10 = 60
Four years ago father was F - 4 yrs old.
Four years ago son was S - 4 yrs old.
Mark sum of their ages four years ago as Σ
Four years ago sum of their ages was:
Σ = F - 4 + S - 4
Σ = F + S - 8
You already know:
F + S = 60
so
Σ = F + S - 8
Σ = 60 - 8 = 52
S = son's present age
After five years father will be F + 5 yrs old.
After five years son will be S + 5 yrs old.
After five years, the sum of their years will be 70.
F + 5 + S + 5 = 70
F + S + 10 = 70
F + S = 70 - 10 = 60
Four years ago father was F - 4 yrs old.
Four years ago son was S - 4 yrs old.
Mark sum of their ages four years ago as Σ
Four years ago sum of their ages was:
Σ = F - 4 + S - 4
Σ = F + S - 8
You already know:
F + S = 60
so
Σ = F + S - 8
Σ = 60 - 8 = 52