Problema Solution
IF JACK OS TWICE AS OLD AS JOHN AND JIN IS THREE YEARS OLDER THAN JOHN,HOW OLD IS JOHN IF THE SUM OF THEIR AGES IS 51?
Answer provided by our tutors
let
x = the age of John
y = the age of Jack
z = the age of Jin
JACK IS TWICE AS OLD AS JOHN
y = 2*x
JIN IS THREE YEARS OLDER THAN JOHN
z = x + 3
THE SUM OF THEIR AGES IS 51
x + y + z = 51
by solving the system of equations
y = 2*x
z = x + 3
x + y + z = 51
we find
x = 12 years
y = 24 years
z = 15 years
John is 12 years old.